Study On Molybdenum Carbide Catalysts For Syngas To Alcohols With Ecological Environment Strategy

It is very urgent for looking green and clean alternative energy with the depletion of fossil energy and environmental pollution. Using biomass energy to developing "green fuel"—alcohol fuel is one of the main ways to solve the problem. It has potential advantage and great prospect on economic and technical aspects that synthesis gas preparation from biomass for alcohol fuel. How to improve the syngas to alcohol reaction activity, reduce exhaust of CH4and CO2as well as energy consumption in the process of syngas to alcohol are urgent problems for future industrialization. A key solution for solving the problem is to develop the syngas to alcohol catalyst with high activity and high selectivity. It is evident from the recent research that the β-Mo2C-based catalysts are with high C2+OH selectivity and thus the most promising catalysts for higher alcohol synthesis.In this paper we prepared supported molybdenum carbide catalysts. The comprehensive evaluation of the catalysts such as syngas to alcohol activity, emissions of CH4and CO2is presented and discussed.3D cage-like structure of mesoporous molecular sieve SBA-16as the carrier, prepared a series of Ni-β-Mo2C-K/SBA-16catalysts by impregnation method. The N2adsorption-desorption isotherms, XRD, TEM measurements were used to characterize the phase, pore structure, element distribution and active sites of the catalysts.We found that the influence of the reaction temperature on the catalytic activity is the most obvious, elevated reaction temperature may increase the rate of CO conversion, C2+OH selectivity and space time yield, but would reduce total alcohol selectivity at the same time. Reaction pressure is minimal effect on the catalytic performance; the pressure is changed within a certain range, almost no influence on the reaction activity. Space velocity range between temperature and pressure effect on the reaction, increasing the space velocity could promote the selectivity of the total alcohol with reducing the CO conversion and C2+OH selectivity. Low Ni content will reduce the C2+OH selectivity, and will generate the hydrocarbon compound with high contents. Therefore, the mass ratio of Ni/Mo=1/8in supported molybdenum carbide catalyst has the highest reactivity. Metal K affects the total alcohol selectivity and C2+OH selectivity. The CO conversion, total alcohol selectivity and C2+OH selectivity are high when K/Mo molar ratio of3/10. The CO conversion rate, the total alcohol selectivity, C2+OH selectivity and space-time yield improved with increasing the Mo content. When the the Mo loading amount30%, Ni/Mo=1/8, K/Mo=3/10, the activity of the supported catalyst Ni-β-Mo2C-K/SBA-16has the best performence. By catalytic reaction, having a3D cage-like pore and containing the larger aperture of the SBA-16mesoporous material can contribute to the catalytic reaction, which could enhance the rate of CO conversion, and total alcohol selectivity and C2+OH selectivity.The supported bimetallic molybdenum carbide catalyst is applied in CH4/CO2reforming reaction, and a production mode was simulated by coupling of the alcohol from syngas device with CH4/CO2reforming unit.