Pd Nanocubes@ZIF‐8: Integration of Plasmon‐Driven Photothermal Conversion with a Metal–Organic Framework for Efficient and Selective Catalysis

Composite nanomaterials usually possess synergetic properties resulting from the respective components and can be used for a wide range of applications. In this work, a Pd nanocubes@ZIF‐8 composite material has been rationally fabricated by encapsulation of the Pd nanocubes in ZIF‐8, a common metal–organic framework (MOF). This composite was used for the efficient and selective catalytic hydrogenation of olefins at room temperature under 1 atm H₂ and light irradiation, and benefits from plasmonic photothermal effects of the Pd nanocube cores while the ZIF‐8 shell plays multiple roles; it accelerates the reaction by H₂ enrichment, acts as a “molecular sieve” for olefins with specific sizes, and stabilizes the Pd cores. Remarkably, the catalytic efficiency of a reaction under 60 mW cm^?2 full‐spectrum or 100 mW cm^?2 visible‐light irradiation at room temperature turned out to be comparable to that of a process driven by heating at 50 °C. Furthermore, the catalyst remained stable and could be easily recycled. To the best of our knowledge, this work represents the first combination of the photothermal effects of metal nanocrystals with the favorable properties of MOFs for efficient and selective catalysis.     

树枝状钯纳米结构的控制合成及硝基苯加氢反应的催化活性

以氯钯酸为前驱体, 苯甲醇为还原剂和溶剂, 十六烷基吡咯烷酮(PVP)为稳定剂, 在微波辐射下制备了分散均匀、形貌均一的树枝状钯纳米结构. 产物用透射电子显微镜(TEM), X射线粉末衍射(XRD), X射线光电子能谱(XPS)进行了表征, 表明所制备的Pd纳米颗粒呈树枝状, 形貌单一, 分散均匀, 是由许多近似圆形的小颗粒自组装而成的二级结构. 对树枝状钯催化硝基苯加氢反应进行探究, 表明树枝状钯的催化活性比市售的钯碳催化剂的催化活性高.     

Metal Bromide Controlled Interfacial Aromatization Reaction for Shape‐Selective Synthesis of Palladium Nanostructures with Efficient Catalytic Performances

Herein, the effect of diverse metal bromides for the shape evolution of palladium nanostructures (Pd NS) has been demonstrated. Aromaticity‐driven reduction of bromopalladate(II) is optimized to reproducibly obtain different Pd NS at the water/organic layer interface. In this soft interfacial strategy, a redox potential driven reaction has been performed, forming the thermodynamically more stable (>10⁴‐fold) PdBr₄^2? precursor from PdCl₄^2? by adding extra metal bromides. In the process, the reductant, Hantzsch dihydropyridine ester (DHPE), is aromatized. Interestingly, alkali metal bromides devoid of coordination propensity exclusively evolve Pd nanowires (Pd NWs), whereas in the case of transition metal bromides the metal ions engage the ‘N’ donor of DHPE at the interface, making the redox reaction sluggish. Hence, controlled Pd nanoparticles growth is observed, which evolves Pd broccolis (Pd NBRs) and Pd nanorods (Pd NRs) at the interface in the presence of NiBr₂ and CuBr₂, respectively, in the aqueous solution. Thus, the effect of diverse metal bromides in the reaction mixture for tailor‐made growth of the various Pd NS is reported. Among the as‐synthesized materials, the Pd NWs stand to be superior catalysts and their efficiency is almost 6 and 2.5 times higher than commercial 20 % Pd/C in the electrooxidation of ethanol and Cr^VI reduction reaction by formic acid, respectively.     

A General and High‐Yield Galvanic Displacement Approach to Au?M (M=Au,Pd, and Pt) Core–Shell Nanostructures with Porous Shells and Enhanced Electrocatalytic Performances

In this work, we utilize the galvanic displacement synthesis and make it a general and efficient method for the preparation of Au? M (M=Au, Pd, and Pt) core–shell nanostructures with porous shells, which consist of multilayer nanoparticles. The method is generally applicable to the preparation of Au? Au, Au? Pd, and Au? Pt core–shell nanostructures with typical porous shells. Moreover, the Au? Au isomeric core–shell nanostructure is reported for the first time. The lower oxidation states of Au^I, Pd^II, and Pt^II are supposed to contribute to the formation of porous core–shell nanostructures instead of yolk‐shell nanostructures. The electrocatalytic ethanol oxidation and oxygen reduction reaction (ORR) performance of porous Au? Pd core–shell nanostructures are assessed as a typical example for the investigation of the advantages of the obtained core–shell nanostructures. As expected, the Au? Pd core–shell nanostructure indeed exhibits a significantly reduced overpotential (the peak potential is shifted in the positive direction by 44 mV and 32 mV), a much improved CO tolerance (I_f/I_b is 3.6 and 1.63 times higher), and an enhanced catalytic stability in comparison with Pd nanoparticles and Pt/C catalysts. Thus, porous Au? M (M=Au, Pd, and Pt) core–shell nanostructures may provide many opportunities in the fields of organic catalysis, direct alcohol fuel cells, surface‐enhanced Raman scattering, and so forth.     

Selective Hydrogenation of Acrolein Over Pd Model Catalysts: Temperature and Particle‐Size Effects

The selectivity in the hydrogenation of acrolein over Fe₃O₄‐supported Pd nanoparticles has been investigated as a function of nanoparticle size in the 220–270 K temperature range. While Pd(111) shows nearly 100 % selectivity towards the desired hydrogenation of the C=O bond to produce propenol, Pd nanoparticles were found to be much less selective towards this product. In situ detection of surface species by using IR‐reflection absorption spectroscopy shows that the selectivity towards propenol critically depends on the formation of an oxopropyl spectator species. While an overlayer of oxopropyl species is effectively formed on Pd(111) turning the surface highly selective for propenol formation, this process is strongly hindered on Pd nanoparticles by acrolein decomposition resulting in CO formation. We show that the extent of acrolein decomposition can be tuned by varying the particle size and the reaction temperature. As a result, significant production of propenol is observed over 12 nm Pd nanoparticles at 250 K, while smaller (4 and 7 nm) nanoparticles did not produce propenol at any of the temperatures investigated. The possible origin of particle‐size dependence of propenol formation is discussed. This work demonstrates that the selectivity in the hydrogenation of acrolein is controlled by the relative rates of acrolein partial hydrogenation to oxopropyl surface species and of acrolein decomposition, which has significant implications for rational catalyst design.     

Polysiloxane microspheres functionalized with imidazole groups as a palladium catalyst support

Polysiloxane microspheres containing a large number of silanol groups were obtained by an emulsion process of modified polyhydromethylsiloxane. N‐substituted imidazole groups were grafted on these microspheres by the silylation of their silanol groups with N‐[γ‐(dimethylchlorosilyl)propyl]imidazole hydrochloride. The progress of the reaction was monitored using ²⁹Si and ¹³C magic angle spinning (MAS) NMR and its impact on microsphere morphology was studied using scanning electron microscopy (SEM). The usefulness of the imidazole‐functionalized microspheres as a support for a metal catalyst was demonstrated by their reaction with PdCl₂(PhCN)₂. In this way a new heterogenized catalyst, Pd(II) complex with imidazole ligands supported on polysiloxane microspheres, was generated. This catalyst, MPd , was characterized using ¹³C and ²⁹Si MAS NMR, X‐ray photoelectron, Fourier transform infrared and far‐infrared spectroscopies, X‐ray diffraction, SEM–energy‐dispersive X‐ray spectroscopy and wide‐angle X‐ray scattering. The catalyst appears in two structures, as Pd(II) complex and Pd(0) nanoclusters. Its catalytic activity was tested using a model reaction, the hydrogenation of cinnamaldehyde, and compared with that of an analogous complex operating in a homogeneous system. MPd showed a high activity in the promotion of hydrogenation of cinnamaldehyde. The activity in the substrate conversion was stable at least in five cycles of this reaction. The main product was hydrocinnamaldehyde which could be obtained with a yield above 70%. A mechanism of the reaction is proposed. Copyright © 2016 John Wiley & Sons, Ltd.     

In Situ Dispersion of Palladium on TiO2 During Reverse Water–Gas Shift Reaction: Formation of Atomically Dispersed Palladium

The application of single‐atom catalysts (SACs) to high‐temperature hydrogenation requires materials that thermodynamically favor metal atom isolation over cluster formation. We demonstrate that Pd can be predominantly dispersed as isolated atoms onto TiO₂ during the reverse water–gas shift (rWGS) reaction at 400 °C. Achieving atomic dispersion requires an artificial increase of the absolute TiO₂ surface area by an order of magnitude and can be accomplished by physically mixing a precatalyst (Pd/TiO₂) with neat TiO₂ prior to the rWGS reaction. The in situ dispersion of Pd was reflected through a continuous increase of rWGS activity over 92 h and supported by kinetic analysis, infrared and X‐ray absorption spectroscopies and scanning transmission electron microscopy. The thermodynamic stability of Pd under high‐temperature rWGS conditions is associated with Pd‐Ti coordination, which manifests upon O‐vacancy formation, and the artificial increase in TiO₂ surface area.     

Seeded growth core-shell (Ag–Au–Pd) ternary nanostructure at room temperature for potential water treatment

Seed-mediated growth is a promising technique for preparation of multi-metallic nanostructures, in which reduction of metal ions takes a place over the surface of another one. Herein, a seed growth mechanism was investigated for synthesis of core-shell Ag–Au–Pd ternary nanostructures through a facile method at room temperature. Ascorbic acid and sodium alginate were used as nano-generator and stabilizing agent, respectively. Spherical shaped monocular Ag nanostructure with size of 13.6 nm grew to 24.4 nm of Ag–Au binary and to 58.8 nm of Ag–Au–Pd ternary core-shell nanostructures. The crystalline shape of nanostructures was approved by X-Ray diffraction analyses. While, FT-IR data approved the redox mechanism for synthesis the as-required nanostructures. The catalytic reactivity of the prepared nanostructures in reductive degradation of methylene blue dye was studied. The results approved the role of Pd in perfection of catalytic degradation of the as-tested dye. The rate constant of dye degradation was considerably enlarged from 62.1 × 10⁻³ m⁻¹ for Ag monocular nanostructures to 403.3 × 10⁻³ m⁻¹ for Ag–Pd binary and to 852.4 × 10⁻³ m⁻¹ for Ag–Au–Pd ternary core-shell nanostructures. The obtained results offer an energy saving method to fabricate core-shell catalytically active ternary nanostructures with promising applicability in water treatment.     

Development of a Practical and Scalable Preparation using Sonication of Pd/Fibroin Catalyst for Chemoselective Hydrogenation

A practical and efficient preparation method of palladium‐fibroin (Pd/Fib), silk‐fibroin‐supported Pd(0) by means of sonication, has been developed. The Pd/Fib catalyst could be prepared within 12 h at room temperature starting from commercial silk‐fibroin and Pd(OAc)₂ in MeOH, whereas our previous preparation method required at least 4 days. The present improved process is applicable to a large‐scale preparation of Pd/Fib. The Pd/Fib prepared by the present method also catalyzed chemoselective hydrogenation of acetylenes, olefins, and azides in the presence of aromatic ketones, aldehydes, and halides; N‐Cbz protective groups; and benzyl esters, which are readily hydrogenated under the Pd/C‐ or Pd/C(en)‐catalyzed hydrogenation conditions.     

Dealloying to Nanoporous Silver and Its Implementation as a Template Material for Construction of Nanotubular Mesoporous Bimetallic Nanostructures

Nanoporous silver (NPS) is fabricated by selectively dissolving Al from AgAl alloys in corrosive electrolytes at room temperature. Electron spectroscopy characterizations demonstrate that the NaOH electrolyte is beneficial to the formation of a three‐dimensional bicontinuous porous nanostructure with uniform and tunable pore and ligament dimensions of a few tens of nanometers, while processing in HCl electrolyte easily lead to coarsened porous nanostructures. The high‐surface‐area Ag nanostructures are demonstrated as novel effective template materials to the construction of nanotubular mesoporous Pt/Ag and Pd/Ag alloy structures, which are realized via room temperature galvanic replacement reactions with H₂PtCl₆ and K₂PdCl₄ solutions by adding a high concentration of Cl^? ions as a coordinating agent. Electrochemical measurements indicate that the resulting hollow and porous bimetallic nanostructures show enhanced electrocatalytic activities and CO‐tolerance with better durability toward methanol and formic acid oxidation due to alloying with Ag.     

Enhanced catalytic performance of Pd‐Ga bimetallic catalysts for 2‐ethylanthraquinone hydrogenation

A series of Pd and Pd‐Ga bimetallic catalysts were prepared by a co‐impregnation method for 2‐ethylanthraquinone (EAQ) hydrogenation to produce hydrogen peroxide. Compared with 0.6Pd catalyst, the hydrogenation efficiency of 0.6Pd1.2Ga catalyst (11.9 g L^?1) increases by 32.2%, and the stability of 0.6Pd1.2Ga catalyst is also higher than that of 0.6Pd catalyst. The structures of the samples were determined by N₂ adsorption–desorption, ICP, XRD, CO chemisorption, TEM, H₂‐TPR, in situ CO‐DRIFTS and XPS. The results suggest that incorporation of Ga species improves Pd dispersion and generates a strong interaction between Ga₂O₃ and Pd interface or between Pd and support. DFT calculation results indicate that the strong adsorption of carbonyl group on Ga₂O₃/Pd interface facilitates the activation of EAQ and promotes the hydrogenation efficiency.     

Selective hydrogenation of cinnamaldehyde over carbon nanotube supported pd-ru catalyst

Summary Carbon nanotube supported Pd, Ru and Pd-Ru catalysts have been prepared and tested with the hydrogenation of cinnamaldehyde as a probe reaction. It has been found that the cinnamaldehyde conversion and the selectivity towards the hydrogenation of C=O bond over Pd-Ru/PCNT catalyst could reach 56.6% and 79.1%, respectively, at 120^oC and 5.0 MPa, which is better than Pd/PCNT and Ru/PCNT catalysts under the same reaction conditions. It is assumed that the better performance of Pd-Ru/PCNT catalyst for cinnamaldehyde hydrogenation may be due to the synergic effect of Pd and Ru metals or the promoting effect of Ru metal.     

Catalytic properties of transition metal salts immobilized on nanoporous silica polyamine composites II: hydrogenation

The transition metal compounds Pd(OAc)₂, RhCl₃·4H₂O and RuCl₃ · nH₂O were adsorbed onto the nanoporous silica polyamine composite (SPC) particles (150–250 µm), WP‐1 [poly(ethyleneimine) on amorphous silica], BP‐1 [poly(allylamine) on amorphous silica], WP‐2 (WP‐1 modified with chloroacetic acid) and BP‐2 (BP‐1 modified with chloroacetic acid). Inductively coupled plasma‐atomic emission spectrometry analysis of the dried samples after digestion indicated metal loadings of 0.4–1.2 mmol g^?1 except for RhCl₃·4H₂O on BP‐2 which showed a metal loading of only 0.1 mmol g^?1. The metal loaded composites were then screened as hydrogenation catalysts for the reduction of 1‐octene, 1‐decene, 1‐hexene and 1, 3‐cyclohexadiene at a hydrogen pressure of 5 atm in the temperature range of 50–90 °C. All 12 combinations of SPC and transition metal compound proved active for the reduction of the terminal olefins, but isomerization to internal alkenes was competitive in all cases. Under these conditions, selective hydrogenation of 1,3‐cyclohexadiene to cyclohexene was observed with some of the catalysts. Turnover frequencies were estimated for the hydrogenation reactions based on the metal loading and were in some cases comparable to more conventional heterogeneous hydrogenation catalysts. Examination of the catalysts before and after reaction with X‐ray photoelectron spectroscopy and transmission electron microscopy revealed that, in the cases of Pd(OAc)₂ on WP‐2, BP‐1 and BP‐2, conversion of the surface‐ligand bound metal ions to metal nano‐particles occurs. This was not the case for Pd(OAc)₂ on WP‐1 or for RuCl₃ · nH₂O and RhCl₃· 4H₂O on all four composites. The overall results are discussed in terms of differences in metal ion coordination modes for the composite transition‐metal combinations. Suggested ligand interactions are supported by solid state CPMAS ¹³C NMR analyses and by analogy with previous structural investigations of metal binding modes on these composite materials. Copyright © 2011 John Wiley & Sons, Ltd.     

Metal@COFs: Covalent Organic Frameworks as Templates for Pd Nanoparticles and Hydrogen Storage Properties of Pd@COF‐102 Hybrid Material

Three‐dimensional covalent organic frameworks (COFs) have been demonstrated as a new class of templates for nanoparticles. Photodecomposition of the [Pd(η³‐C₃H₅)(η⁵‐C₅H₅)]@COF‐102 inclusion compound (synthesized by a gas‐phase infiltration method) led to the formation of the Pd@COF‐102 hybrid material. Advanced electron microscopy techniques (including high‐angle annular dark‐field scanning transmission electron microscopy and electron tomography) along with other conventional characterization techniques unambiguously showed that highly monodisperse Pd nanoparticles ((2.4±0.5) nm) were evenly distributed inside the COF‐102 framework. The Pd@COF‐102 hybrid material is a rare example of a metal‐nanoparticle‐loaded porous crystalline material with a very narrow size distribution without any larger agglomerates even at high loadings (30 wt %). Two samples with moderate Pd content (3.5 and 9.5 wt %) were used to study the hydrogen storage properties of the metal‐decorated COF surface. The uptakes at room temperature from these samples were higher than those of similar systems such as Pd@metal–organic frameworks (MOFs). The studies show that the H₂ capacities were enhanced by a factor of 2–3 through Pd impregnation on COF‐102 at room temperature and 20 bar. This remarkable enhancement is not just due to Pd hydride formation and can be mainly ascribed to hydrogenation of residual organic compounds, such as bicyclopentadiene. The significantly higher reversible hydrogen storage capacity that comes from decomposed products of the employed organometallic Pd precursor suggests that this discovery may be relevant to the discussion of the spillover phenomenon in metal/MOFs and related systems.     

Pt‐Pd‐Co Trimetallic Alloy Network Nanostructures with Superior Electrocatalytic Activity towards the Oxygen Reduction Reaction

Pt alloy nanostructures show great promise as electrocatalysts for the oxygen reduction reaction (ORR) in fuel cell cathodes. Herein, three‐dimensional (3D) Pt‐Pd‐Co trimetallic network nanostructures (TNNs) with a high degree of alloying are synthesized through a room temperature wet chemical synthetic method by using K₂PtCl₄/K₃Co(CN)₆–K₂PdCl₄/K₃Co(CN)₆ mixed cyanogels as the reaction precursor in the absence of surfactants and templates. The size, morphology, and surface composition of the Pt‐Pd‐Co TNNs are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected‐area electron diffraction (SAED), energy dispersive spectroscopy (EDS), EDS mapping, X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS). The 3D backbone structure, solid nature, and trimetallic properties of the mixed cyanogels are responsible for the 3D structure and high degree of alloying of the as‐prepared products. Compared with commercially available Pt black, the Pt‐Pd‐Co TNNs exhibit superior electrocatalytic activity and stability towards the ORR, which is ascribed to their unique 3D structure, low hydroxyl surface coverage and alloy properties.     

Metal–organic framework derived Pd/ZrO2@CN as a stable catalyst for the catalytic hydrogenation of 2,3,5‐trimethylbenzoquinone

Metal–organic frameworks (MOFs) have recently been identified as versatile sacrificing templates to construct functional nanomaterials for heterogeneous catalysis. Herein, we report a thermal transformation strategy to directly fabricate metal Pd nanoclusters inlaid within a ZrO₂@nitrogen‐doped porous carbon (Pd/ZrO₂@CN) composite using Pd@NH₂‐UiO‐66(Zr) as a precursor that was pre‐synthesized by a one‐pot hydrothermal method. The developed Pd/ZrO₂@CN as a robust catalyst delivered remarkable stability and activity to the catalytic hydrogenation of 2,3,5‐trimethylbenzoquinone (TMBQ) to 2,3,5‐trimethylhydroquinone (TMHQ), a key reaction involved in vitamin E production. The hydrogenation was carried out at 110 °C with 1.0 MPa H₂, and it resulted in 98% TMHQ yield as the sole product over five consecutive cycles, outperforming the analogue Pd/ZrO₂@C without nitrogen doping templated from Pd@UiO‐66(Zr). The excellent catalytic properties of Pd/ZrO₂@CN likely originated from the highly stable ultrafine Pd nanoclusters inlaid within ZrO₂@CN matrix on account of the strong interaction between N and Pd, as well as on the Lewis acidity of ZrO₂, which was beneficial to the hydrogenation.     

Quantum chemical analysis of mechanisms of phenylacetylene and styrene hydrogenation to ethylbenzene on the Pd{111} surface

The mechanisms of the hydrogenation of phenylacetylene and styrene to ethylbenzene on the Pd{111} surface, which are secondary reactions of the selective hydrogenation of phenylacetylene, were studied by the DFT-PBE method. The position of the Ph group of the styrene molecule with respect to the Pd surface is shown to exert a noticeable effect on the mechanism of the process. If the Ph group is adsorbed on the Pd surface, then the addition of the first H atom to the terminal C atom of the styrene molecule is most probable. If Ph does not contact the surface, then the most substituted C atom of the styrene molecule is first hydrogenated. On the whole, the interaction of the Ph group with the Pd{111} surface results in stable adsorption structures, the hydrogenation of which on the Pd{111} surface is strongly hindered. The Gibbs activation energy (ΔG^≠₂₉₈) is 22.9 and 27.1 kcal mol^–1 in the most probable reaction routes of styrene hydrogenation to ethylbenzene and direct hydrogenation of phenylacetylene to ethylbenzene, respectively.     

H+−H− Pairs in Partially Oxidized MAX Phases for Bifunctional Catalytic Conversion of Furfurals into Linear Ketones

Currently, less favorable C=O hydrogenation and weak concerted acid catalysis cause unsatisfactory catalytic performance in the upgrading of biomass-derived furfurals (i.e., furfural, 5-methyl furfural, and 5-hydroxymethyl furfural) to ketones (i.e., cyclopentanone, 2,5-hexanedione, and 1-hydroxyl-2,5-hexanedione). A series of partially oxidized MAX phase (i.e., Ti₃AlC₂, Ti₂AlC, Ti₃SiC₂) supporting Pd catalysts were fabricated, which showed high catalytic activity; Pd/Ti₃AlC₂ in particular displayed high performance for conversion of furfurals into targeted ketones. Detailed studies of the catalytic mechanism confirm that in situ hydrogen spillover generates Frustrated Lewis H⁺−H⁻ pairs, which not only act as the hydrogenation sites for selective C=O hydrogenation but also provide acid sites for ring opening. The close intimate hydrogenation and acid sites promote bifunctional catalytic reactions, substantially reducing the reported minimum reaction temperature of various furfurals by at least 30–60 °C.     

Influence of Metallic Modification on Ethylbenzene Dealkylation over ZSM‐5 Zeolites

A series of metal‐modified HZSM‐5 catalysts were prepared by impregnation and were used for ethylbenzene dealkylation of the mixed C8 aromatics (ethylbenzene, m‐xylene and o‐xylene). The effects of different supported metals (Pt, Pd, Ni, Mo) on catalytic performance, including reaction conditions, were investigated. The physicochemical properties of catalysts were characterized by means of XRD, BET, TEM and NH₃‐TPD. Experimental results showed that metallic modification obviously increased the ethylbenzene conversion and reduced the coke deposition, greatly improving the catalyst stability. The distinction of ethylbenzene conversion depended on the interaction between hydrogenation reactivity and acidic cracking of bifunctional metal‐modified zeolites. Compared with Pt and Ni, Pd and Mo were easier to disperse into HZSM‐5 micropores during loading metals. The acidic density of different metal‐modified HZSM‐5 declined in the following order: HZSM‐5>Pt/HZSM‐5>Pd/HZSM‐5>Ni/HZSM‐5>Mo/HZSM‐5. The activity of ethylene hydrogenation decreased with Pt/HZSM‐5>Pd/HZSM‐5>Ni/HZSM‐5>Mo/HZSM‐5. In comparison, Pd/HZSM‐5 showed the best catalytic performance with both high activity and high selectivity, with less cracking loss of m‐xylene and o‐xylene. Moreover, the following reaction conditions were found to be preferable for ethylbenzene dealkylation over Pd/HZSM‐5: 340°C, 1.5 MPa H₂, WHSV 4 h^?1, H₂/C8 4 mol/mol.     

The Role of Pd2+/Pd0 in Hydrogenation by [Pd(2‐pymo)2]n: An X‐ray Absorption and IR Spectroscopic Study

The metal–organic framework (MOF) [Pd(2‐pymo)₂]_n (2‐pymo=2‐pyrimidinolate) was used as catalyst in the hydrogenation of 1‐octene. During catalytic hydrogenation, the changes at the metal nodes and linkers of the MOF were investigated by in situ X‐ray absorption spectroscopy (XAS) and IR spectroscopy. With the help of extended X‐ray absorption fine structure and X‐ray absorption near edge structure data, Quick‐XAS, and IR spectroscopy, detailed insights into the catalytic relevance of Pd²⁺/Pd⁰ in the hydrogenation of 1‐octene could be achieved. Shortly after exposure of the catalyst to H₂ and simultaneously with the hydrogenation of 1‐octene, the aromatic rings of the linker molecules are hydrogenated rapidly. Up to this point, the MOF structure remained intact. After completion of linker hydrogenation, the linkers were also protonated. When half of the linker molecules were protonated, the onset of reduction of the Pd²⁺ centers to Pd⁰ was observed and the hydrogenation activity decreased, followed by fast reduction of the palladium centers and collapse of the MOF structure. Major fractions of Pd⁰ are only observed when the hydrogenation of 1‐octene is almost finished. Consequently, the Pd²⁺ nodes of the MOF [Pd(2‐pymo)₂]_n are identified as active centers in the hydrogenation of 1‐octene.