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论文类型： 期刊论文

发表时间： 2018-01-01

发表刊物： ACS CATALYSIS

收录刊物： SCIE、EI

卷号： 8

期号： 1

页面范围： 90-100

ISSN号： 2155-5435

关键字： CO2 conversion; nonthermal plasmas; plasma catalysis; CO2 hydrogenation; methanol synthesis; ambient conditions; synergistic effect

摘要： CO2 hydrogenation to methanol is a promising process for CO2 conversion and utilization. Despite a well-developed route for CO hydrogenation to methanol, the use of CO2 as a feedstock for methanol synthesis remains underexplored, and one of its major challenges is high reaction pressure (usually 30-300 atm). In this work, atmospheric pressure and room temperature (similar to 30 degrees C) synthesis of methanol from CO2 and H-2 has been successfully achieved using a dielectric barrier discharge (DBD) with and without a catalyst. The methanol production was strongly dependent on the plasma reactor setup; the DBD reactor with a special water-electrode design showed the highest reaction performance in terms of the conversion of CO2 and methanol yield. The combination of the plasma with Cu/gamma-Al2O3 or Pt/gamma-Al2O3 catalyst significantly enhanced the CO2 conversion and methanol yield compared to the plasma hydrogenation of CO2 without a catalyst. The maximum methanol yield of 11.3% and methanol selectivity of 53.7% were achieved over the Cu/gamma-Al2O3 catalyst with a CO2 conversion of 21.2% in the plasma process, while no reaction occurred at ambient conditions without using plasma. The possible reaction mechanisms in the plasma CO2 hydrogenation to CH3OH with and without a catalyst were proposed by combined means of electrical and optical diagnostics, product analysis, catalyst characterization, and plasma kinetic modeling. These results have successfully demonstrated that this unique plasma process offers a promising solution for lowering the kinetic barrier of catalytic CO2 hydrogenation to methanol instead of using traditional approaches (e.g., high reaction temperature and high-pressure process), and has great potential to deliver a step-change in future CO2 conversion and utilization.