Cloud point extraction preconcentration for capillary electrophoresis of metal ions

The application of the cloud point extraction (CPE) technique for capillary electrophoresis (CE) determination of metal ions was demonstrated using Cu(II) and Co(II) as model metal ions. The preconcentration of Cu(II) and Co(II) in aqueous solution was achieved by CPE with 1-(2-pyridylazo)-2-naphthol (PAN) as the chelating agent and Triton X-114 as the extractant. Baseline separation of the PAN chelates of Cu(II) and Co(II) was realized by CE with a photodiaode array detector in a  μm i.d. fused-silica capillary at 17 kV. A 50 mM NH₄Ac buffer solution (pH 8.0) containing 0.2 mM of PAN in 80% (v/v) of acetonitrile and 20% (v/v) doubly deionized water (DDW) was used as the separation medium to avoid the adsorption of hydrophobic substances and nonionic surfactant Triton X-114 onto the inner surface of the separation capillary, ensuring the separation efficiency and reproducibility. The precision (relative standard deviation (R.S.D.), n=5) for five replicate injections of a mixture of 20 μg/l of Co(II) and Cu(II) were 0.74 and 1.8% for the migration time, 3.1 and 0.64% for the peak area measurement, respectively. The apparent concentration factor, which is defined as the concentration ratio of the analyte in the final diluted surfactant-rich extract ready for CE separation and in the initial solution, was 15.9 for Co(II) and 16.3 for Cu(II). The linear concentration range was from 3 to 100 μg/l for both Co(II) and Cu(II). The detection limits of Co(II) and Cu(II) were 0.12 and 0.26 μg/l, respectively. The developed method was successfully applied to the determination of Co(II) and Cu(II) in tap water, snow water, and flavor wines.     

Phosphorylated polyacrylonitrile‐based electrospun nanofibers for removal of heavy metal ions from aqueous solution

The phosphorylated polyacrylonitrile‐based (P‐PAN) nanofibers were prepared by electrospinning technique and used for removal of Cu²⁺, Ni²⁺, Cd²⁺, and Ag⁺ from aqueous solution. The morphological and structural properties of P‐PAN nanofibers were characterized by scanning electron microscope and Fourie transform infrared spectra. The P‐PAN nanofibers were evaluated for the adsorption capacity at various pH, contact time, and reaction temperature in a batch system. The reusability of P‐PAN nanofibers for the removal of heavy metal ions was also determined. Adsorption isotherms and adsorption kinetics were also used to examine the fundamental adsorption properties. It is found that the P‐PAN nanofibers show high efficiency, and the maximal adsorption capacities of metal ions as calculated from the Langmuir model were 92.1, 68.3, 14.8, and 51.7 mg/g, respectively. The kinetics of the heavy metal ions adsorption were found to follow pseudo‐second‐order rate equation, suggesting chemical adsorption can be regarded as the major factor in the adsorption process. Sorption/desorption results reveal that the obtained P‐PAN nanofibers can remain high removal efficiency after four cycles.     

Removal of heavy metal ions from aqueous solution using Fe3O4-SiO2-poly(1,2-diaminobenzene) core-shell sub-micron particles

In this work, Fe₃O₄-SiO₂-poly(1,2-diaminobenzene) sub-micron particles (FSPs) with high saturated magnetization of ∼60-70 emu/g were developed and utilized for the removal of As(III), Cu(II), and Cr(III) ions from aqueous solution. The isothermal results fitted well with the Freundlich model and the kinetic results fitted well with the two-site pseudo-second-order model, which indicated that multilayer adsorption of As(III), Cu(II), and Cr(III) ions on FSPs occurred at two sites with different energy of adsorption. The maximum adsorption capacities followed the order of As(III) (84 ± 5 mg/g, pH = 6.0) > Cr(III) (77 ± 3 mg/g, pH = 5.3) > Cu(II) (65 ± 3 mg/g, pH = 6.0). And the chelating interaction was considered as the main adsorption mechanism. The as-prepared materials were chemically stable with low leaching of Fe (?1.7 wt.%) and poly(1,2-diaminobenzene) (?4.9 wt.%) in tap water, sea water, and acidic/basic solutions. These metal-loaded FSPs could be easily recovered from aqueous solutions using a permanent magnet within 20 s. They could also be easily regenerated with acid. The present work indicates that the FSPs are promising for removal of heavy metal ions in field application.     

Carbon nanofibers with nanoporosity and hollow channels from binary polyacrylonitrile systems

Carbon nanofibers with new structural features, e.g. nanoporosity, hollow, U-shape cross-section, were generated by utilizing the phase separation behavior of polymer additive with polyacrylonitrile (PAN). The approach involved the formation of precursor fibers by electrospinning of binary mixtures of PAN with poly(ethylene oxide) (PEO), cellulose acetate (CA) or poly(methyl methacrylate) (PMMA), the removal of the polymer and the carbonization of the remaining PAN. The carbon nanofiber yield was ca 50% of PAN in all cases. Nanoporous carbon nanofibers with an average diameter of 100 nm were generated from the water treated PAN/PEO precursors. Multi-channel hollow fibers (90-190 nm diameters) were produced from the acetone treated PAN/CA precursors. Carbon fibers produced from the chloroform treated PAN/PMMA precursors were 250-400 nm in diameters and consisted of varied hollow structures, i.e., hollow and U-shape cross-sections from those containing 30% and 50% PAN, respectively, and multi-channel hollow fibers from the 70/30 PAN/PMMA precursor. Carbonization of equal-mass PAN/PMMA as-spun fibers also produced similarly U-shape cross-sections as the chloroform treated ones, showing promise of direct carbonization. This simple and yet versatile approach to create new structural features in carbonized fibers has shown to depend on the distinct phase separation as well as the pyrolytic behaviors of the second polymer component.     

Chemically modified silica gel with aminothioamidoanthraquinone for solid phase extraction and preconcentration of Pb(II), Cu(II), Ni(II), Co(II) and Cd(II)

Silica gel chemically bonded with aminothioamidoanthraquinone was synthesized and characterized. The metal sorption properties of modified silica were studied towards Pb(II), Cu(II), Ni(II), Co(II) and Cd(II). The determination of metal ions was carried out on FAAS. For batch method, the optimum pH ranges for Pb(II), Cu(II) and Cd(II) extraction were ≥3 but for Ni(II) and Co(II) extraction were ≥4. The contact times to reach the equilibrium were less than 10 min. The adsorption isotherm fitted the Langmuir's model showed the maximum sorption capacities of 0.56, 0.30, 0.15, 0.12 and 0.067 mmol/g for Pb(II), Cu(II), Ni(II), Co(II) and Cd(II), respectively. In the flow system, a column packed modified silica at 20 mg for Pb(II) and Cu(II), 50 mg for Cd(II), 60 mg for Co(II), Ni(II) was studied at a flow rate of 4 and 2.5 mL/min for Ni(II). The sorbed metals were quantitatively eluted by 1% HNO₃. No interference from Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl⁻ and SO₄²⁻ at 10, 100 and 1000 mg/L was observed. The application of this modified silica gel to preconcentration of pond water, tap water and drinking water gave high accuracy and precision (%R.S.D. ≤ 9). The method detection limits were 22.5, 1.0, 2.9, 0.95, 1.1 μg/L for Pb(II), Cu(II), Ni(II), Co(II) and Cd(II), respectively.     

Determination of manganese by flame atomic absorption spectrometry after its adsorption onto naphthalene modified with 1-(2-pyridylazo)-2-naphthol (PAN)

A system for determination of manganese, after preconcentration with 3% (w/w) 1-(2-pyridylazo)-2-naphthol (PAN), adsorbed on microcrystalline naphthalene is proposed. An amount of 200 mg of this complexing mixture is placed in a glass column and conditioned with a NH₄Cl/NH₄OH buffer solution (pH 9.5). The aqueous sample, containing manganese, is treated with an ammonium tartrate solution, then with a hydroxylammonium chloride solution and, finally, with a buffer solution. The resulting solution is passed through the column containing microcrystalline naphthalene modified with 1-(2-pyridylazo)-2-naphthol (PAN) where Mn(II) is retained. The column is first washed with deionized water and then with 10.0 ml of dimethylformamide to dissolve the Mn(II)-PAN/naphthalene complex. Manganese is determined by air-acetylene flame atomic absorption spectrometry. About 1 μg of manganese can be concentrated from 200 ml of aqueous sample, allowing a preconcentration factor of 20, a limit of quantification of 5 ng ml⁻¹ and R.S.D. of 3.8%. The accuracy was ascertained using certified reference materials, including samples of urine and glass. Water samples were also analysed and the results are in good agreement with those obtained by graphite furnace atomic absorption spectrometry.     

Removal of heavy metal ions from water by using poly(ethyleneglycol dimethacrylate-co-acrylamide) beads

Poly(ethyleneglycol dimethacrylate-co-acrylamide) (poly(EDGMA-co-AAm)) copolymer beads have been prepared for use in the separation Pb(II), Hg(II), and Cd(II), metal ions in aqueous solution by a batch equilibration technique. Adsorption capacity were increased with pH for Pb(II), Cd(II) and Hg(II) and then reached almost plateau value around 6.0. The high initial rate of metal ions uptake (<10 min) suggests that the adsorption occurs mainly at the bead surface. The metal uptake results show that poly(EGDMA-co-AAm) can be used for the adsorption of the following metals in the indicated order: Pb(II) > Cd(II) > Hg(II) expressed on a molar basis. However, when the uptake was expressed in terms of the amount of metal removed from solution was as follows: Pb(II) > Hg(II) > Cd(II). The beads still showed preference toward Pb(II) when this metal was in a mixture with Hg(II) and Cd(II). A linearized form of the Freundlich and the Langmuir isotherm model fits the experimental equilibrium concentration data of Hg(II) and Cd(II) better than isotherm type model of Pb(II). The recovery of the metal ions after adsorption and the regeneration of the adsorbent can be carried out by treatment of the loaded beads with either 0.5 M NaCl, or 1 M HNO₃.     

Use of 1-(2-pyridylazo)-2-naphthol as the post column reagent for ion exchange chromatography of heavy metals in environmental samples

Ion exchange chromatography (IEC) using a bi-functional column (quaternary ammonium and sulfonate groups), followed by post-column reaction (PCR) with 1-(2-pyridylazo)-2-naphthol (PAN), was used to separate and quantitate Cu(II), Ni(II), Zn(II), Co(II), Cd(II), Mn(II) and Hg(II) at low concentration levels. IEC-PCR separation was achieved within 14 min using the mobile phase containing 3 mmol L^− 1 2,6-pyridinedicarboxylic acid (PDCA) and 3 mmol L^− 1 oxalate at pH 12.5. Effects of pH as well as PAN, detergent and chloride ion concentrations during post-column reaction on detector response were examined. Detection limits were less than 4.5 μg L^− 1 for all metals except Hg(II) (19 μg L^− 1) using spectrophotometric measurements at 550 nm. Analytical validations showed good linearity for detection up to 6.0 mg L^− 1, with R² higher than 0.99. Precisions based on retention time evaluation for intra-day and inter-day measurements with the relative standard deviation (RSD) were less than 2.9% and 3.6%, respectively. The method gave good accuracy with the recoveries ranged from 80.5 to 105% for all metal ions studied. The proposed method was applied to the analysis of metal ions in environmental samples (leachate, soil and sediment) in Northeastern Thailand. The results were in good agreement with atomic spectroscopic measurements on the same samples.     

Decoration of electrospun polyacrylonitrile nanofibers with ZnO nanoparticles and their application for removal of Pb ions from waste water

The adsorption behavior of lead (II) from aqueous solutions utilizing ZnO/polyacrylonitrile (PAN) nanofibers was studied. ZnO/PAN nanofibers were prepared by electrospinning method. The changes of the parameters of adsorbent amount, pH, contact time, and temperature were tested in the adsorption experiments. The adsorption was well described by the Langmuir adsorption isotherm model. The thermodynamic parameters indicate that the adsorption process is exothermic. The dynamic behavior of the lead (II) ions adsorption by PAN/ZnO nanofibers was well described by the pseudo-second-order kinetic model. The adsorbent can be regenerated by suitable desorption processes for multiple uses without significant loss of its adsorption capacity.     

Development of new adsorbent chitin for column preconcentration and spectrophotometric trace determination of Ziram and Zineb in synthetic, commercial samples and food-stuffs

A procedure has been developed for the determination of zinc(II) bis(dimethyldithiocarbamate) (Ziram) or zinc(II) ethylenebisdithiocarbamate (Zineb) present in a large volume of aqueous solution after preconcentration on a column using chitin-1-(2′pyridylazo)-2-naphthol (PAN) as adsorbent. Ziram/Zineb are quantitatively retained on the column as Zn-PAN complex in the pH range 9.0-11.0 and at a flow rate of 1-8 ml/min. Complex adsorbed on chitin was eluted from the column with dimethylformamide (DMF) and absorbance of the eluate was measured at 550 nm against a reagent blank. Beer's law is obeyed over the concentration range 5.3-55.8 μg of Ziram and 6.8-49.0 μg of Zineb in 25 ml of the final DMF solution. Ten replicate determinations on a sample solution containing 45.22 μg of Ziram or 40.86 μg of Zineb gave a mean absorbance of 0.30 with a relative standard deviation 1.6 and 1.8%, respectively. The interference of various ions has been studied. Many alkali metals and metal salts do not interfere. The method has been employed to the determination of Ziram and Zineb in commercial samples and in various foodstuffs and the results were compared with the earlier reported methods.     

Chemically-modified activated carbon with ethylenediamine for selective solid-phase extraction and preconcentration of metal ions

A new method that utilizes ethylenediamine-modified activated carbon (AC-EDA) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) prior to the measurement by inductively coupled plasma optical emission spectrometry (ICP-OES). The new sorbent was prepared by oxidative surface modification. Experimental conditions for effective adsorption of trace levels of Cr(III), Fe(III), Hg(II) and Pb(II) were optimized with respect to different experimental parameters using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4.0. Complete elution of absorbed metal ions from the sorbent surface was carried out using 3.0 mL of 2% (%w/w) thiourea and 0.5 mol L⁻¹ HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.4, 28.9, 60.5 and 49.9 mg g⁻¹ for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The time for 94% adsorption of target metal ions was less than 2 min. The detection limits of the method was found to be 0.28, 0.22, 0.09 and 0.17 ng mL⁻¹ for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The precision (R.S.D.) of the method was lower 4.0% (n = 8). The prepared sorbent as solid-phase extractant was successfully applied for the preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) in natural and certified samples with satisfactory results.     

Optimization of polyacrylonitrile-cysteine resin synthesis and its selective removal of Cu(Ⅱ) in aqueous solutions

Polyacrylonitrile beads(PAN) cysteine(CS) was synthesized from polyacrylonitrile beads(PAN) and cysteine(CS).The content of the functional group and the percentage conversion of the functional group of PAN-CS prepared under the optimum condition using response surface methodology(RSM) for the first attempt were 3.22 mmol/g and 35.78%.The structure was characterized by ET-IR and elemental analysis.The adsorption properties of the resin for Cu(Ⅱ) were investigated by batch and column experiments.Batch adsorption results suggested that PAN-CS had higher adsorption capability for Cu(Ⅱ)than other metal ions and maximum saturated adsorption capacity was 184.7 mg/g.The resin and its metal complexes were studied by FT-IR.Furthermore,the resin can be eluted easily using 1 mol/L HC1.PAN-CS can provide a potential application for selective removal of copper from waste solution.     

偕胺肟化聚丙烯腈纳米纤维的制备及在含金属离子废水处理中的应用

利用电纺丝技术制备了聚丙烯腈纳米纤维无纺布, 然后在水溶液原位偕胺肟化得到偕胺肟化聚丙烯腈纳米纤维, 该纳米纤维可用于吸附再生含金属离子废水. 采用氯化铜溶液模拟含金属离子废水, 探讨不同肟化率的偕胺肟化纳米纤维对铜离子的吸附效果; 发现肟化率78.8%的偕胺肟化纳米纤维的吸附能力最好, 利用Langmuir吸附方程得到最大吸附值为56.5 mg/g, 同时吸附后可将含铜废水浓度从100 mg/L降至13 μg/L, 远远低于国标GB8978-1996规定的铜排放的一级标准(总铜浓度<0.5 mg/L). 吸附铜离子的纳米纤维在1 mol/L稀硝酸中, 100 min后铜离子的解吸附率超过98%. 经4次吸附-解吸附循环后, 偕胺肟化纳米纤维的吸附能力仍能达到首次吸附最大吸附值的50%以上, 表明偕胺肟化纳米纤维具有一定的循环再生能力.     

β-环糊精功能化聚丙烯腈纳米纤维的制备及对亚甲基蓝的吸附性能

以N,N-二甲基甲酰胺(DMF)为溶剂,利用静电纺丝法制备了聚丙烯腈(PAN)/β-环糊精(β-CD)纳米纤维.通过场发射扫描电镜、红外光谱和粉末XRD对纳米纤维进行了表征,并检测了纺丝溶液的电导率和黏度.结果表明,β-CD的添加量可以改善纳米纤维的形貌,固定在纤维上的β-CD保留了空腔结构,为其在纳米纤维中发挥超分子...     

β-环糊精功能化聚丙烯腈纳米纤维的制备及对亚甲基蓝的吸附性能β-环糊精功能化聚丙烯腈纳米纤维的制备及对亚甲基蓝的吸附性能

以N,N-二甲基甲酰胺(DMF)为溶剂, 利用静电纺丝法制备了聚丙烯腈(PAN)/β-环糊精(β-CD)纳米纤维. 通过场发射扫描电镜、红外光谱和粉末XRD对纳米纤维进行了表征, 并检测了纺丝溶液的电导率和黏度. 结果表明, β-CD的添加量可以改善纳米纤维的形貌, 固定在纤维上的β-CD保留了空腔结构, 为其在纳米纤维中发挥超分子特性提供了可能. 通过紫外-可见光谱法研究了PAN/β-CD纤维对亚甲基蓝(MB)溶液的吸附性能. 结果表明, 纳米纤维中的β-CD显著提高了PAN/β-CD纤维对MB的吸附能力, 使其在吸附分离、电化学传感器及药物控制释放等领域具有潜在的应用价值.     

Solid phase extraction of metal ions using carbon nanotubes

The sorption behaviour of carbon nanotubes (CNTs) toward some divalent metal ions such as Cu(II), Co(II), Ni(II), Zn(II), Pb(II), Mn(II) and Cd(II) has been investigated systematically. The affinity order of the metal ions towards CNTs at pH in the range of 7.0-9.0 was: Cu(II) > Pb(II) > Zn(II) > Co(II) > Ni(II) > Cd(II) > Mn(II). The experimental parameters for preconcentration of copper, which exhibits the highest affinity towards carbon nanotubes, on a microcolumn packed with CNTs prior to its determination by flame atomic absorption spectrometry have been investigated. Copper can be quantitatively retained at pH 8.2 from sample volume up to 150 mL and then eluted completely with 0.1 mol L^− 1 HNO₃. The limit of detection limit for Cu(II) determination with FAAS detection was 2.1 μg L^− 1, and the RSD was 3.5% at the 50 μg L^− 1 level. Under the optimal conditions for copper enrichment also Zn(II), Pb(II) and Ni(II) could be quantitatively preconcentrated from water samples. The method was validated using a certified reference materials BCR-610 and SRM 1640.     

Thermochemistry of adducts of some bivalent transition metal bromides with aniline

The compounds [MBr₂(an)₂] (where M is Mn(II), Fe(II), Co(II), Ni(II), Cu(II) or Zn(II); an = aniline) were synthesized and characterized by melting points, elemental analysis, thermal studies, and electronic and IR spectroscopy. The enthalpies of dissolution of the adducts, metal(II) bromides and aniline in methanol, aqueous 1.2 M HCl or 25% (v/v) aqueous 1.2 M HCl in methanol were measured. The following thermochemical parameters for the adducts have been determined by thermochemical cycles: the standard enthalpies for the Lewis acid/base reactions (Δ_rH°), the standard enthalpies of formation (Δ_fH°), the standard enthalpies of decomposition (Δ_DH°), the lattice standard enthalpies (Δ_MH°) and the standard enthalpies of the Lewis acid/base reactions in the gaseous phase (Δ_rH°(g)). The mean bond dissociation enthalpies of the M(II)-nitrogen bonds () and the enthalpies of formation of the adducts from the ions in the gaseous phase: M²⁺_(g) + Br⁻_(g) + an_(g) → [MBr₂(an)₂]_(g), (Δ_fiH°) have been estimated.     

Solid-phase extraction and preconcentration of cadmium(II) in aqueous solution with Cd(II)-imprinted resin (poly-Cd(II)-DAAB-VP) packed columns

A novel chelating resin (poly-Cd(II)-DAAB-VP) was prepared by metal ion imprinted polymer (MIIP) technique. The resin was obtained by one pot reaction of Cd(II)-diazoaminobenzene-vinylpyridine with cross-linker ethyleneglycoldimethacrylate (EGDMA). Comparing with non-imprinted resin, the poly-Cd(II)-DAAB-VP has higher adsorption capacity and selectivity for Cd(II). The distribution ratio (D) values for the Cd(II)-imprinted resin show increase for Cd(II) with respect to both D values of Zn(II), Cu(II), Hg(II) and non-imprinted resin. The relatively selective factor (α_r) values of Cd(II)/Cu(II), Cd(II)/Zn(II) and Cd(II)/Hg(II), are 51.2, 45.6, and 85.4, which are greater than 1. poly-Cd(II)-DAAB-VP can be used at least 20 times without considerable loss of adsorption capacity. Based on poly-Cd(II)-DAAB-VP packed columns, a highly selective solid-phase extraction (SPE) and preconcentration method for Cd(II) from aqueous solution was developed. The MIIP-SPE preconcentration procedure showed a linear calibration curve within concentration range from 0.093 to 30 μg l⁻¹. The detection limit and quantification limit were 0.093 and 0.21 μg l⁻¹ (3σ) for flame atomic absorption spectrometry (FAAS). The relative standard deviation of the eleven replicate determinations was 3.7% for the determination of 10 μg of Cd(II) in 100 ml water sample. Determination of Cd(II) in certified river sediment sample (GBW 08301) demonstrated that the interfering matrix had been almost removed during preconcentration. The column was good enough for Cd(II) determination in matrixes containing components with similar chemical property such as Cu(II), Zn(II) and Hg(II).     

1-(2-Formamidoethyl)-3-phenylurea functionalized activated carbon for selective solid-phase extraction and preconcentration of metal ions

A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4. And the adsorbed metal ions could be completely eluted by using 2.0 mL 2.0 mol L⁻¹ HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.8, 39.9, 77.8 and 17.3 mg g⁻¹ for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The detection limits of the method were found to be 0.15, 0.41, 0.27 and 0.36 ng mL⁻¹ for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n = 8). The method was successfully applied for the preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) in natural and certified samples with satisfactory results.     

A study on methanol steam reforming to CO2 and H2 over the La2CuO4 nanofiber catalyst

The La₂CuO₄ crystal nanofibers were prepared by using single-walled carbon nanotubes as templates under mild hydrothermal conditions. The steam reforming of methanol (SRM) to CO₂ and H₂ over such nanofiber catalysts was studied. At the low temperature of 150 °C and steam/methanol=1.3, methanol was completely (100%, 13.8 g/h g catalyst) converted to hydrogen and CO₂ without the generation of CO. Within the 60 h catalyst lifespan test, methanol conversion was maintained at 98.6% (13.6 g/h g catalyst) and with 100% CO₂ selectivity. In the meantime, for distinguishing the advantage of nanoscale catalyst, the La₂CuO₄ bulk powder was prepared and tested for the SRM reaction for comparison. Compared with the La₂CuO₄ nanofiber, the bulk powder La₂CuO₄ showed worse catalytic activity for the SRM reaction. The 100% conversion of methanol was achieved at the temperature of 400 °C, with the products being H₂ and CO₂ together with CO. The catalytic activity in terms of methanol conversion dropped to 88.7% (12.2 g/h g catalyst) in 60 h. The reduction temperature for nanofiber La₂CuO₄ was much lower than that for the La₂CuO₄ bulk powder. The nanofibers were of higher specific surface area (105.0 m²/g), metal copper area and copper dispersion. The in situ FTIR and EPR experiments were employed to study the catalysts and catalytic process. In the nanofiber catalyst, there were oxygen vacancies. H₂-reduction resulted in the generation of trapped electrons [e] on the vacancy sites. Over the nanofiber catalyst, the intermediate H₂CO/HCO was stable and was reformed to CO₂ and H₂ by steam rather than being decomposed directly to CO and H₂. Over the bulk counterpart, apart from the direct decomposition of H₂CO/HCO to CO and H₂, the intermediate H₂COO might go through two decomposition ways: H₂COO=CO+H₂O and H₂COO=CO₂+H₂.