A series of SBA-15 supported bimetallic Rh–Ni catalysts with different weight ratio of Rh/Ni in the range of 0–0.04 were prepared for carbon dioxide reforming of methane. The doping effect of Rh on catalytic activity as well as carbon accumulation and removal over the catalysts was studied. The characterization results indicated that the addition of a small amount of Rh promoted the reducibility of Ni particles and decreased the Ni particle size. During the dry reforming reaction, the carbon deposition was originated from CH4 decomposition and CO disproportionation. The Rh–Ni catalyst with small metallic particle size inhibited the carbon formation and exhibited high efficiency in the removal of coke. In comparison with bare Ni-based catalyst, the Rh–Ni bimetallic catalysts showed high activity and stability in the dry reforming of methane.
A series of Co/Mg-Al oxide samples, CoMgAl-x (x = (Mg + Co)]AI molar ratio of 1-5), were prepared by the self-combustion method followed by H2 reduction. The catalytic performance and stability of the samples were studied in dry reforming ofCH4. XRD and H2-TPR characterization results showed that the reduced CoMgAl-x samples mainly consisted of solid solution and spinel phases with cobalt particles. The spinel phases contained COB04 and ConMgl-nAl204 (0 〈 n 〈 1 ) varying with the (Mg + Co)/AI ratio, The effect of (Mg + Co)/A1 molar ratio on the catalytic behavior was investigated in detail and CoMgAI-3 exhibited the highest catalytic activity and stability among the catalysts studied.
Wen-Jia CaiLin-Ping QianBin YueXue-Ying ChenHe-Yong He
Ni/Al2O3 catalysts were derived from spinel NiAl2O4 with different Ni content ((2.5, 5 and 7.5) wt%). The catalysts were obtained by H-2 reduction and were investigated for the low-temperature hydrogenation of maleic anhydride (MA) to produce succinic anhydride (SA). The characterization results showed that Ni-0 active sites were mainly derived during the H2 reduction from spinel NiAl2O4 Among the catalysts studied, employing the optimum preparation and reaction conditions with Ni(5%)/Al2O3 yielded the highest catalytic performance. A near-100% conversion of MA and similar to 90% selectivity to SA were achieved at 120 degrees C and 0.5 MPa of H-2 with a weighted hourly space velocity (MA) of 2 h(-1). (C) 2017, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.
A series of Ce-promoted 6.7%Ni-containing mesoporous silica(Ce-Ni-Si O2)with varying Ce content(0.5%–4.8%)was prepared using the evaporation-induced self-assembly method.The characterization results showed that Ce and Ni species were homogeneously incorporated into the mesoporous silica matrix.The catalytic properties of these samples in the dry reforming of methane reaction revealed that the catalysts(e.g.,1.2%Ce-Ni-Si O2)containing highly dispersed small Ni particles exhibited excellent catalytic activity and long-term stability,which is attributed to the anchoring effect of the Ce and its ability to increase surface oxygen species concentration.