Efficient Ni-based catalysts for low-temperature reverse water-gas shift (RWGS) reaction

CO₂ hydrogenation for syngas can alleviate the pressure of un-controlled emissions of CO₂ and bring enormous economic benefits. Advantageous Ni-catalysts have good CO₂ hydrogenation activity and high CO selectivity merely over 700 °C. Herein, we introduced Cu into Ni catalysts, which were evaluated by H₂-TPR, XRD, BET, in-situ XPS and CO₂-TPD, and their CO₂ hydrogenation activity and CO selectivity were significantly affected by the Ni/Cu ratios, which was rationalized by the synergistic effect of bimetallic catalysts. In addition, the reduction temperatures of studied catalysts apparently affected the CO₂ hydrogenation, which were caused by the number and dispersion of the active species. It's found that the Ni₁Cu₁-400 had good stability, high CO selectivity (up to 90%), and fast formation rate (1.81×10⁻⁵ mol/g_cat/s) at 400 °C, which demonstrated a good potential as a superior catalyst for reverse water-gas shift (RWGS) reaction.     

Boosting CO2 Hydrogenation to Formate over Edge-Sulfur Vacancies of Molybdenum Disulfide

Synthesis of formate from hydrogenation of carbon dioxide (CO₂) is an atom-economic reaction but is confronted with challenges in developing high-performance non-precious metal catalysts for application of the process. Herein, we report a highly durable edge-rich molybdenum disulfide (MoS₂) catalyst for CO₂ hydrogenation to formate at 200 °C, which delivers a high selectivity of over 99 % with a superior turnover frequency of 780.7 h⁻¹ surpassing those of previously reported non-precious metal catalysts. Multiple experimental characterization techniques combined with theoretical calculations reveal that sulfur vacancies at MoS₂ edges are the active sites and the selective production of formate is enabled via a completely new water-mediated hydrogenation mechanism, in which surface OH* and H* species in dynamic equilibrium with water serve as moderate hydrogenating agents for CO₂ with residual O* reduced by hydrogen. This study provides a new route for developing low-cost high-performance catalysts for CO₂ hydrogenation to formate.     

MgO‐ZrO2 Mixed Oxides as Effective and Reusable Base Catalysts for Glucose Isomerization into Fructose in Aqueous Media

MgO‐ZrO₂ mixed oxides prepared with different Mg/Zr atomic ratios (denoted as xMZ: where x is the atomic ratio of Mg/Zr) are investigated for the glucose isomerization to fructose in water at 95 °C. The highest fructose yield of 33 % is obtained over 0.76MZ with ≈74 % selectivity after 3 h. To gain insight into the structure–activity relationships, the prepared catalysts are characterized by N₂ physisorption, XRD, FTIR and CO₂‐TPD. The results indicate that the addition of MgO drastically changed the textual property of ZrO₂ and increased the number of basic sites. The kinetic studies revealed that the Lewis basic sites (cus‐O^2?) generated from the highly dispersed MgO are the active sites responsible for the enhanced isomerization activity. Notably, MZ is reusable for four runs without a significant decrease in catalyst activity. Accordingly, this study provides an easily prepared, cheap, and recyclable catalyst that may hold great potential for fructose production.     

乙酰丙酸选择性加氢合成γ-戊内酯中高效和可循环使用的Ni3Fe NPs@C 双金属催化剂

生物质经催化转化合成燃料及化学品是当前研究的热点.目前,生物质的催化转化主要聚焦于纤维素、半纤维素和木质素的解聚及其下游产物合成.其中,乙酰丙酸(LA)作为纤维素解聚的主要产物之一,是一种极具竞争力的平台化合物和重要的生物质转化中间体.LA通过催化转化可以合成各类高附加值的化学品,例如,通过催化加氢LA可选择性合成γ-戊内酯(GVL).所合成的GVL用途广泛,可作为绿色溶剂、食品、燃料添加剂、(塑料、高分子、烃类或者其它高附加值化学品)前驱体等.目前,LA-to-GVL的研究主要着眼于非均相催化体系,包括负载型贵金属和非贵金属催化剂体.其中,贵金属催化剂主要有Ru,Au,Pd,Rh,Ir和Pt,虽然催化效率高,条件温和,但是成本高,难以实现工业化.此外对于广泛使用的Ru/C催化剂,存在金属-载体间相互作用不强.活性组分易流失、导致催化剂稳定性差等问题;而非贵金属则普遍存在催化活性不佳及反应条件苛刻等缺点.因此,开发高效、稳定、反应条件温和且具有工业化应用前景的非贵金属催化剂具有显著的研究意义,这也是当前的研究趋势.在特定温度下,金属离子与碳基底存在较强的相互作用.鉴于此,本文通过一步碳热还原法合成了活性炭负载的Ni3Fe双金属催化剂(Ni3Fe NPs@C).该催化剂在LA-to-GVL转化体系中展现了直接加氢(DH)和转移加氢(TH)双功能催化特性.首先,考察了其在DH体系中的反应特性:在130oC和2 MPa氢压反应条件下经2 h反应,LA转化率达到93.8％,GVL选择性为95.5％,GVL产率是相应的单金属Ni/C和Fe/C催化剂的6倍和40倍.此外,在TH催化反应体系中,在180oC,0.5 h和无外加氢源的反应条件下,以异丙醇为反应溶剂和供氢体,LA几乎完全转化为GVL,其反应效率同样相较于单金属Ni/C和Fe/C催化剂大幅度提高.所合成的Ni3Fe NPs@C双金属催化剂DH和TH催化性能优于绝大多数报道的LA加氢贵金属和非贵金属催化剂.而且,该催化剂具有良好的循环利用性能,经过四次循环,其结构和化学状态没有发生明显的改变,稳定性明显优于商业化的Ru/C催化剂.此外,通过系统分析其催化性能以及材料结构,明确了该催化剂在LA的DH和TH反应体系中的活性位点,并提出了可能的反应路径.该研究为其它类型的DH和TH反应体系以及生物质高效转化过程提供了新的催化剂设计思路.并且这种催化剂及其制备方法简单、绿色,易于工业化推广和应用.     

Highly Productive CNN Pincer Ruthenium Catalysts for the Asymmetric Reduction of Alkyl Aryl Ketones

Chiral pincer ruthenium complexes of formula [RuCl(CNN)(Josiphos)] ( 2 – 7 ; Josiphos=1‐[1‐(dicyclohexylphosphano)ethyl]‐2‐(diarylphosphano)ferrocene) have been prepared by treating [RuCl₂(PPh₃)₃] with (S,R)‐Josiphos diphosphanes and 1‐substituted‐1‐(6‐arylpyridin‐2‐yl)methanamines (HCNN; substituent=H ( 1 a ), Me ( 1 b ), and tBu ( 1 c )) with NEt₃. By using 1 b and 1 c as a racemic mixture, complexes 4 – 7 were obtained through a diastereoselective synthesis promoted by acetic acid. These pincer complexes, which display correctly matched chiral PP and CNN ligands, are remarkably active catalysts for the asymmetric reduction of alkyl aryl ketones in basic alcohol media by both transfer hydrogenation (TH) and hydrogenation (HY), achieving enantioselectivities of up to 99 %. In 2‐propanol, the enantioselective TH of ketones was accomplished by using a catalyst loading as low as 0.002 mol % and afforded a turnover frequency (TOF) of 10⁵–10⁶ h^?1 (60 and 82 °C). In methanol/ethanol mixtures, the CNN pincer complexes catalyzed the asymmetric HY of ketones with H₂ (5 atm) at 0.01 mol % relative to the complex with a TOF of ≈10⁴ h^?1 at 40 °C.     

On the Functional Group Tolerance of Ester Hydrogenation and Polyester Depolymerisation Catalysed by Ruthenium Complexes of Tridentate Aminophosphine Ligands

The synthesis of a range of phosphine‐diamine, phosphine‐amino‐alcohol, and phosphine‐amino‐amide ligands and their ruthenium(II) complexes are reported. Five of these were characterised by X‐ray crystallography. The activities of this collection of catalysts were initially compared for the hydrogenation of two model ester hydrogenations. Catalyst turnover frequencies up to 2400 h^?1 were observed at 85 °C. However, turnover is slow at near ambient temperatures. By using a phosphine‐diamine Ru^II complex, identified as the most active catalyst, a range of aromatic esters were reduced in high yield. The hydrogenation of alkene‐, diene‐, and alkyne‐functionalised esters was also studied. Substrates with a remote, but reactive terminal alkene substituent could be reduced chemoselectively in the presence of 4‐dimethylaminopyridine (DMAP) co‐catalyst. The chemoselective reduction of the ester function in conjugated dienoate ethyl sorbate could deliver (2E,4E)‐hexa‐2,4‐dien‐1‐ol, a precursor to leaf alcohol. The monounsaturated alcohol (E)‐hex‐4‐en‐1‐ol was produced with reasonable selectivity, but complete chemoselectivity of C?O over the diene is elusive. High chemoselectivity for the reduction of an ester over an alkyne group was observed in the hydrogenation of an alkynoate for the first time. The catalysts were also active in the depolymerisation reduction of samples of waste poly(ethylene terephthalate) (PET) to produce benzene dimethanol. These depolymerisations were found to be poisoned by the ethylene glycol side product, although good yields could still be achieved.     

Chemo-bio catalyzed synthesis of <Emphasis Type="Italic">R</Emphasis>-1-phenylethyl acetate over bimetallic PdZn catalysts,lipase, and Ru/Al<Subscript>2</Subscript>O<Subscript>3</Subscript>. part I

One-pot synthesis of R-1-phenyethylacetate at 70°C was investigated using three different catalysts simultaneously, namely a bimetallic PdZn/Al₂O₃ as a hydrogenation catalyst, an immobilized lipase as an acylation catalyst and Ru/Al₂O₃ as a racemization catalyst. The most active bimetallic catalyst was PdZn/Al₂O₃ calcined at 300°C and reduced at 400°C, whereas the most selective although less active catalyst was the one being calcined and reduced at 500°C. The highest selectivity to R-1-phenylethyl acetate over this catalyst was 32 at 48% conversion. Ru/Al₂O₃ was confirmed to have a positive effect on the formation of the desired product, although it was not very active in the racemization during one-pot synthesis.     

Highly Active and Robust Metalloporphyrin Catalysts for the Synthesis of Cyclic Carbonates from a Broad Range of Epoxides and Carbon Dioxide

Bifunctional metalloporphyrins with quaternary ammonium bromides (nucleophiles) at the meta, para, or ortho positions of meso‐phenyl groups were synthesized as catalysts for the formation of cyclic carbonates from epoxides and carbon dioxide under solvent‐free conditions. The meta‐substituted catalysts exhibited high catalytic performance, whereas the para‐ and ortho‐substituted catalysts showed moderate and low activity, respectively. DFT calculations revealed the origin of the advantage of the meta‐substituted catalyst, which could use the flexible quaternary ammonium cation at the meta position to stabilize various anionic species generated during catalysis. A zinc(II) porphyrin with eight nucleophiles at the meta positions showed very high catalytic activity (turnover number (TON)=240 000 at 120 °C, turnover frequency (TOF)=31 500 h^?1 at 170 °C) at an initial CO₂ pressure of 1.7 MPa; catalyzed the reaction even at atmospheric CO₂ pressure (balloon) at ambient temperature (20 °C); and was applicable to a broad range of substrates, including terminal and internal epoxides.     

In-Situ-Formed Potassium-Modified Nickel-Zinc Carbide Boosts Production of Higher Alcohols beyond CH4 in CO2 Hydrogenation

Ni-based catalysts have been widely studied in the hydrogenation of CO₂ to CH₄, but selective and efficient synthesis of higher alcohols (C₂₊OH) from CO₂ hydrogenation over Ni-based catalyst is still challenging due to successive hydrogenation of C1 intermediates leading to methanation. Herein, we report an unprecedented synthesis of C₂₊OH from CO₂ hydrogenation over K-modified Ni−Zn bimetal catalyst with promising activity and selectivity. Systematic experiments (including XRD, in situ spectroscopic characterization) and computational studies reveal the in situ generation of an active K-modified Ni−Zn carbide (K-Ni₃Zn₁C_0.7) by carburization of Zn-incorporated Ni⁰, which can significantly enhance CO₂ adsorption and the surface coverage of alkyl intermediates, and boost the C−C coupling to C₂₊OH rather than conventional CH₄. This work opens a new catalytic avenue toward CO₂ hydrogenation to C₂₊OH, and also provides an insightful example for the rational design of selective and efficient Ni-based catalysts for CO₂ hydrogenation to multiple carbon products.     

Water‐Enhanced Synthesis of Higher Alcohols from CO2 Hydrogenation over a Pt/Co3O4 Catalyst under Milder Conditions

The effect of water on CO₂ hydrogenation to produce higher alcohols (C₂–C₄) was studied. Pt/Co₃O₄, which had not been used previously for this reaction, was applied as the heterogeneous catalyst. It was found that water and the catalyst had an excellent synergistic effect for promoting the reaction. High selectivity of C₂–C₄ alcohols could be achieved at 140 °C (especially with DMI (1,3‐dimethyl‐2‐imidazolidinone) as co‐solvent), which is a much lower temperature than reported previously. The catalyst could be reused at least five times without reducing the activity and selectivity. D₂O and ¹³CH₃OH labeling experiments indicated that water involved in the reaction and promoted the reaction kinetically, and ethanol was formed via CH₃OH as an intermediate.     

Ni-intAlx催化剂的化学合成及萘选择加氢性能

非（类）金属掺杂金属形成金属间隙或金属间化合物是一种设计高效、高选择性催化剂的重要手段.我们以萘基锂为强还原剂,NiCl₂与AlCl₃为原料,在室温下化学合成了Ni-^intAl_x纳米催化剂,并采用pXRD、N₂物理吸附、XPS、TEM、H₂-TPR、H₂-TPD等手段对催化剂进行表征.以萘选择加氢为探针反应,结果显示Ni-^intAl_x催化剂对萘选择加氢制四氢萘具有高活性及单一选择性.其中Ni-^intAl₁催化剂具有比Ni样品更纯的FCC晶型,比Ni-^intAl_1/3更适宜的铝掺杂量,及比Ni-^intAl₃更适宜的活性组分含量.镍铝之间的电子效应在一定程度上可调变中间产物四氢萘的吸附性能,避免过度加氢,在优化条件下萘转化率和四氢萘选择性分别达97%和98%,铝可用作第二金属掺杂以提高金属位点的活性和对中间产物的选择性.     

Hydrogen Doping into MoO3 Supports toward Modulated Metal–Support Interactions and Efficient Furfural Hydrogenation on Iridium Nanocatalysts

As promising supports, reducible metal oxides afford strong metal–support interactions to achieve efficient catalysis, which relies on their band states and surface stoichiometry. In this study, in situ and controlled hydrogen doping (H doping) by means of H₂ spillover was employed to engineer the metal–support interactions in hydrogenated MoO_x‐supported Ir (Ir/H?MoO_x) catalysts and thus promote furfural hydrogenation to furfuryl alcohol. By easily varying the reduction temperature, the resulting H doping in a controlled manner tailors low‐valence Mo species (Mo⁵⁺ and Mo⁴⁺) on H?MoO_x supports, thereby promoting charge redistribution on Ir and H?MoO_x interfaces. This further leads to clear differences in H₂ chemisorption on Ir, which illustrates its potential for catalytic hydrogenation. As expected, the optimal Ir/H?MoO_x with controlled H doping afforded high activity (turnover frequency: 4.62 min^?1) and selectivity (>99 %) in furfural hydrogenation under mild conditions (T=30 °C, P =2 MPa), which means it performs among the best of current catalysts.     

Electrocatalytic Reduction of CO2 to Acetic Acid by a Molecular Manganese Corrole Complex

The controlled electrochemical reduction of carbon dioxide to value added chemicals is an important strategy in terms of renewable energy technologies. Therefore, the development of efficient and stable catalysts in an aqueous environment is of great importance. In this context, we focused on synthesizing and studying a molecular Mn^III‐corrole complex, which is modified on the three meso‐positions with polyethylene glycol moieties for direct and selective production of acetic acid from CO₂. Electrochemical reduction of Mn^III leads to an electroactive Mn^II species, which binds CO₂ and stabilizes the reduced intermediates. This catalyst allows to electrochemically reduce CO₂ to acetic acid in a moderate acidic aqueous medium (pH 6) with a selectivity of 63 % and a turn over frequency (TOF) of 8.25 h^?1, when immobilized on a carbon paper (CP) electrode. In terms of high selectivity towards acetate, we propose the formation and reduction of an oxalate type intermediate, stabilized at the Mn^III‐corrole center.     

Low temperature carbon monoxide catalytic oxidation at the Pd/Ce–Zr–Al–Ox catalyst

The homogeneous chemical composition ceria–zirconia–alumina (Ce–Zr–Al–O_x) nano-alloy were successfully synthesized by surfactant-assisted parallel flow co-precipitation method and applied as supports for low temperature CO oxidation. The experiment conditions were studied in detailed. At 0.92 wt% Pd loading, 30,000 ppm CO could be completely oxidized to CO₂ at 30 °C at a WHSV of 4,380 ml g^?1 h^?1 over the Pd/Ce–Zr–Al–O_x (n_Ce:n_Zr = 3:1) catalyst. Pd/Ce–Zr–Al–O_x catalysts were systematical studied by mean of BET, XRD and TEM analysis. XRD characterization showed that zirconium element entered into cubic structure of ceria and leaded to structure distortion. Addition of aluminum increased specific surface area of ceria–zirconia solid solution substantially. The average pore diameter of Ce–Zr–Al–O_x support palladium catalysts were the key impact factor for CO oxidation. When the Pd/Ce–Zr–Al–O_x catalysts had highly dispersed palladium nanoparticles, large average pore diameter, suitable surface area and pore volume, the activity of CO oxidation was the best.     

The effect of the precursor structure on the catalytic properties of the nickel—chromium catalysts of hydrogenation reactions

The influence of the Ni²⁺/Cr³⁺ ratio in the precursor compound on the formation of the catalyst structure and its transformation upon the thermal treatment and reductive activation in hydrogen was studied. The precursors with the cation ratio Ni²⁺/Cr³⁺ = (2.3–3)/1 represent a homogeneous system of the stichtite-type structure. The treatment of the precursors at T ～400 °C in an inert atmosphere forms a nanosized phase of the NiO-type structure with the lattice parameter a = 4.186±0.005 Å. At 600 °C the lattice parameter of this phase decreases to the tabulated value (a = 4.177±0.005 Å). The phase of nickel chromite of the cubic spinel structure with the lattice parameter a = 8.320±0.005 Å is also observed. Hydrogen activation of the catalyst preheated at 300 °C in an inert gas leads to the formation of Ni⁰ crystallites with a size of ～5.5 nm and a specific surface area of ～7.0 m² g^?1. This catalyst exhibits high activity and selectivity in benzene hydrogenation and preferential CO hydrogenation in the presence of CO₂. The catalysts with the ratio Ni²⁺/Cr³⁺ = 1/(2?3) containing nickel and chromium hydroxocarbonates as precursors are less active in the hydrogenation of benzene to cyclohexane.     

Synthesis and Characterization of High Surface Area Tin Oxide Nanoparticles via the Sol‐Gel Method as a Catalyst for the Hydrogenation of Styrene

A systematic study on the preparation of SnO₂ nanoparticles using a simple sol‐gel technique has been conducted by varying reaction parameters such as concentration of ammonia, ammonia feed rate and reaction temperature. The tin oxide obtained was characterized by using FTIR, BET, XRD and TEM. Particles size was obtained in the range of 4 to 5.6 nm and the surface area was found to be between 76 to 114 m² g^?1 depending on the reaction parameters. Meanwhile, the catalytic activity of SnO2 was first time investigated for the hydrogenation reaction of styrene using ethanol as the solvent at 70 °C and 1 atmospheric pressure. It is found that SnO2 acts as a good catalyst in this hydrogenation process. The product conversions in the presence of catalysts prepared at different conditions were between 37 to 72%.     

Bimetallic Co–Ni/TiO<Subscript>2</Subscript> catalysts for selective hydrogenation of cinnamaldehyde

Bimetallic Co–Ni catalysts in the composition range Co_(1?x)Ni_x with x?=?0.0, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8 and 1.0, with total metal loading of 15% w/w and supported on TiO₂-P25, have been prepared by chemical reduction of the metal acetates by glucose in aqueous alkaline medium and characterized by XRD, TEM, TPR, XPS and H₂-TPD techniques. Selective hydrogenation of cinnamaldhyde (CAL) to hydrocinnamaldehyde (HCAL), cinnamyl alcohol (COL) and hydrocinnamyl alcohol (HCOL) has been investigated at 20 bar pressure, in the temperature range 120–140 °C. Co/Ni crystallite sizes in the range 6.0?±?1 nm are observed by TEM. TPR and XPS results indicate the formation of nanoscale Co–Ni alloys, which tend to weaken M–H bond strength, as revealed by H₂-TPD measurements. Ni/TiO₂ displays very high conversion of CAL (86.9%) with high selectivity (78.7%) towards HCAL formation at 140 °C. Co/TiO₂, on the other hand, exhibits relatively lower CAL conversion (55%) and higher selectivity (61.3%) for COL formation at the same temperature. However, bi-metallic Co–Ni catalysts in the composition range x?=?0.3–0.6 display very high conversion (>?98%) due to alloy formation and weakening of M–H bonds. Bimetallic Co_0.7Ni_0.3 catalyst displays high conversion of CAL (98.1%) and high selectivity (82.9%) towards HCOL. Overall CAL hydrogenation activity at 140 °C, when expressed as TOF, displays a maximum value at the composition Co_0.5Ni_0.5. Activity and selectivity patterns have been rationalized based on the reaction pathways observed on the catalysts and the influence of Co–Ni alloy formation and M–H bond strength. Thus, a synergetic effect, originating from an appropriate composition of base metal catalysts and reaction conditions, could result in hydrogenation activity comparable with noble metal based catalysts.     

Low-Temperature Hydrogenation of CO2 to Methanol in Water on ZnO-Supported CuAu Nanoalloys

Optimizing processes and materials for the valorization of CO₂ to hydrogen carriers or platform chemicals is a key step for mitigating global warming and for the sustainable use of renewables. We report here on the hydrogenation of CO₂ in water on ZnO-supported CuAu nanoalloys, based on ≤7 mol % Au. Cu_xAu_y/ZnO catalysts were characterized using ¹⁹⁷Au Mössbauer, in situ X-ray absorption (Au L_III- and Cu K-edges), and ambient pressure X-ray photoelectron (APXP) spectroscopic methods together with X-ray diffraction and high-resolution electron microscopy. At 200 °C, the conversion of CO₂ showed a significant increase by 34 times (from 0.1 to 3.4 %) upon increasing Cu₉₃Au₇ loading from 1 to 10 wt %, while maintaining methanol selectivity at 100 %. Limited CO selectivity (4–6 %) was observed upon increasing temperature up to 240 °C but associated with a ≈3-fold increase in CO₂ conversion. Based on APXPS during CO₂ hydrogenation in an H₂O-rich mixture, Cu segregates preferentially to the surface in a mainly metallic state, while slightly charged Au submerges deeper into the subsurface region. These results and detailed structural analyses are topics of the present contribution.     

Regulation of Coordination Number over Single Co Sites: Triggering the Efficient Electroreduction of CO2

The design of active, selective, and stable CO₂ reduction electrocatalysts is still challenging. A series of atomically dispersed Co catalysts with different nitrogen coordination numbers were prepared and their CO₂ electroreduction catalytic performance was explored. The best catalyst, atomically dispersed Co with two‐coordinate nitrogen atoms, achieves both high selectivity and superior activity with 94 % CO formation Faradaic efficiency and a current density of 18.1 mA cm^?2 at an overpotential of 520 mV. The CO formation turnover frequency reaches a record value of 18 200 h^?1, surpassing most reported metal‐based catalysts under comparable conditions. Our experimental and theoretical results demonstrate that lower a coordination number facilitates activation of CO₂ to the CO₂^.? intermediate and hence enhances CO₂ electroreduction activity.     

溶胶-凝胶法制备NixCo1-xCoAlO4尖晶石型复合氧化物及其催化分解N2O性能

用溶胶凝胶法制备了一组Ni_xCo_1-xCoAlO₄尖晶石型复合氧化物,并采用表面润湿浸渍K₂CO₃溶液进行了K掺杂改性,用于有氧气氛下的N₂O催化分解反应.采用N₂物理吸附、X-射线衍射(XRD)、扫描电镜(SEM)、H₂-程序升温还原(H₂-TPR)等技术对催化剂进行了表征,考察了催化剂组成、母液pH值、K负载量等制备参数对其催化活性的影响.结果表明,母液pH值为3、K/(Ni+Co)物质的量比为0.1的K/Ni_0.15Co_0.85CoAlO₄催化剂具有较高的N₂O分解活性,450 ℃ N₂O可完全分解.助剂K的加入弱化了催化剂表面金属氧键,提高了催化剂的还原性、催化活性和抗水性.