Hierarchical Copper‐Decorated Nickel Nanocatalysts Supported on La₂O₃ for Low‐Temperature Steam Reforming of Ethanol

Abstract

Copper/nickel nanocatalysts with a unique morphology were prepared by thermal reduction of a perovskite LaNix Cu1-x O3 precursor (x=1, 0.9, and 0.7). During thermal reduction, copper was first reduced and reacted with lanthanum to form metastable Cu5 La and Cu13 La. When the thermal reduction temperature was increased, the perovskite decomposed to Ni and La2 O3 , CuLa alloys disappeared, and Cu deposits on Ni nanoparticles were generated, thereby forming Cu/Ni nanocatalysts with hierarchical structures. Nanosized nickel, decorated with copper and supported on La2 O3 , could be produced at 520-550 °C. The steam reforming of ethanol was used as a model reaction to demonstrate the catalytic capability of the materials formed. The hierarchical structure of the Cu/Ni/La2 O3 catalysts confers synergetic effects that greatly favor the dehydrogenation of ethanol and which break the C-C bond to produce a higher yield of hydrogen at a low reaction temperature, whereas La2 O3 provides the required stability during the reaction. The reaction at 290 °C achieved almost 100 % conversion with a hydrogen yield reaching 2.21 molH2 mol(-1) EtOH thus indicating that this special structural feature can achieve high activity for the SRE at low temperatures. The proposed synthesis of nanocatalysts appears to be a good way to generate oxide-supported hierarchically structured nanoparticles that can also be applied to other reactions catalyzed by a heterogeneous metal oxide system.

Template Free Synthesis of Ni-Perovskite: An Efficient Catalyst for Hydrogen Production by Steam Reforming of Bioglycerol

“…Since Ni 0 crystallites are active species for steam reforming reaction, all the catalysts reduced with H 2 before reaction. , The reducibility of the prepared catalysts was investigated by H 2 -TPR, and the reduction profiles are shown in Figure . The TPR profile of LaNiO 3 (E) showed two main reduction peaks at 375 and 560 °C, and the lower temperature peak with the shoulder at 300 °C is assigned to the reduction of LaNiO 3 to La 4 Ni 3 O 10 , followed by La 2 NiO 4 . , The second peak corresponds to the reduction of La 2 NiO 4 to Ni 0 . , Similar reduction profiles were observed for the catalyst prepared without template (LaNiO 3 ); however, both the reduction peaks are shifted slightly toward lower temperature region. TPR results demonstrated that reduction of nickel in the perovskite structure is difficult at low temperature.…”

Synthesis and evaluation of highly dispersed SBA-15 supported Ni–Fe bimetallic catalysts for steam reforming of biomass derived tar reaction

“…One of the factors includes partial re-oxidation of the sample in air during the transfer of samples for analysis in the XPS chamber. 41 Furthermore, Force et al and Kondarides et al showed that the existence of strong metal- a Specific surface area by BET analysis. b Total pore volume estimated at P/P 0 = 0.99. c Average pore diameter calculated by Barrett-Joyner-Halenda (BJH) method.…”

Sensitive electrochemical nonenzymatic glucose sensing based on anodized CuO nanowires on three-dimensional porous copper foam

“…The X-ray photoelectron spectroscopy (XPS) of Cu 2p core level of CuO NWs/CF was presented in Fig. 2g , where two peaks located at 934.2 and 954.2 eV can be assigned to the binding energy of Cu 2p 3/2 and Cu 2p 1/2 respectively, indicating the presence of the Cu 2+ on the sample 33 34 . In addition, two extra shake-up satellite peaks for Cu 2p 3/2 and Cu 2p 1/2 at 942.1 and 962.2 eV were also observed at higher binding energy side, implying the presence of an unfilled Cu 3d 9 shell and thus further confirming the existence of Cu 2+ on the sample surface.…”