Atmospheric Pressure and Room Temperature Synthesis of Methanol through Plasma-Catalytic Hydrogenation of CO2
Atmospheric Pressure and Room Temperature Synthesis of Methanol through Plasma-Catalytic Hydrogenation of CO2
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DOI：
10.1021/acscatal.7b02733
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发表时间：
2018-01-01
期刊：
影响因子：
12.9
通讯作者：
Tu, Xin
中科院分区：
文献类型：
--
作者：
Wang, Li;Yi, Yanhui;Tu, Xin
CO2加氢制甲醇是一种很有前途的CO2转化利用工艺。尽管CO氢化为甲醇的路线已经开发得很好，但使用CO2作为甲醇合成的原料仍然未得到充分探索，并且其主要挑战之一是高反应压力（通常为30-300 atm）。在这项工作中，大气压和室温（类似于30摄氏度）合成甲醇从CO2和H-2已成功地实现了使用介质阻挡放电（DBD）有和没有催化剂。甲醇生产强烈依赖于等离子体反应器设置;具有特殊水电极设计的DBD反应器在CO2转化率和甲醇产率方面表现出最高的反应性能。与没有催化剂的CO2等离子体加氢相比，等离子体与Cu/γ-Al 2 O3或Pt/γ-Al 2 O3催化剂的组合显着提高了CO2转化率和甲醇产率。在Cu/γ-Al_2 O_3催化剂上，等离子体处理时，CO_2转化率为21.2%，甲醇收率最高为11.3%，甲醇选择性为53.7%，而在常温下不使用等离子体时，没有发生反应。通过光电诊断、产物分析、催化剂表征和等离子体动力学建模等手段，提出了等离子体CO2加氢制CH 3OH的可能反应机理。这些结果已经成功地证明，这种独特的等离子体工艺提供了一种有前途的解决方案，用于降低催化CO2氢化为甲醇的动力学屏障，而不是使用传统的方法（例如，高反应温度和高压工艺），并且具有在未来CO2转化和利用中实现阶跃变化的巨大潜力。
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.