화학공학소재연구정보센터
Fuel, Vol.137, 155-163, 2014
Highly efficient NiAl2O4-free Ni/gamma-Al2O3 catalysts prepared by solution combustion method for CO methanation
Ti-doped Ni/gamma-Al2O3 catalysts with Ti loadings varying from 0 wt% to 5 wt% were prepared in glycol by solution combustion method for CO methanation. Compared to Ni/gamma-Al2O3 catalyst, Ti-doped Ni/gamma-Al2O3 catalysts exhibited higher activity. In particular, an optimal Ti-doped Ni/gamma-Al2O3 catalyst with Ti content of 3 wt% (G-3Ti) achieved almost 100% CO conversion and similar to 98.7% CH4 selectivity at 300 degrees C, 0.1 MPa, and a WHSV of 12,000 mL g(-1) h(-1), and showed good stability at 600 degrees C. On analysis of characterization results, Ti species was found effectively restrict the formation of NiAl2O4 spinel phase, leading to a higher utilization of Ni species and thus more exposed active surfaces, which enhanced the CO adsorption capacity. In addition, the electron cloud density of Ni was increased by electron transfer from TiOx, which could facilitate the dissociation of CO on the catalyst surfaces. Moreover, solvents (i.e., ethanol, n-propanol and glycol) also significantly affected the physical-chemical properties of the catalysts, and catalyst prepared in glycol exhibited better catalytic performance for CO methanation. (C) 2014 Elsevier Ltd. All rights reserved.