Abstract:
The CO preferential oxidation reaction (CO-PROX) is an effective strategy to remove residual poisonous CO in proton exchange membrane fuel cells, in which oxygen vacancies play a critical role in CO adsorption and activation. Herein, a series of CuO/CeO2 catalysts derived from Ce-MOFs precursors were synthesized using different organic ligands via the hydrothermal method and the CO-PROX performance was investigated. The CuO/CeO2-135 catalyst derived from homophthalic tricarboxylic acid (1,3,5-H3BTC) exhibited superior catalytic performance with 100 % CO conversion at a relatively low temperature (T100% = 100 °C), with a wide reaction temperature range and excellent stability. The superior catalytic properties were attributed to the structural improvements provided by the 1,3,5-H3BTC precursors and the promotional effects of oxygen vacancies. Additionally, in-situ Raman spectroscopy was performed to verify the dynamic roles of oxygen vacancies for CO adsorption and activation, while in-situ DRIFTS analysis revealed key intermediates in the CO-PROX reaction, shedding light on the mechanistic aspects of the catalytic process. This work not only demonstrates insights into the effective CuO/CeO2 catalysts for CO preferential oxidation, but also provides a feasible way to synthesize MOF-derived catalysts.
摘要:
CO优先氧化反应(CO-PROX)是去除质子交换膜燃料电池中残留有毒CO的有效策略。其中氧空位在CO吸附和活化中起关键作用。在这里,使用不同的有机配体,通过水热法合成了一系列由Ce-MOFs前驱体衍生的CuO/CeO2催化剂,并研究了CO-PROX性能。源自同位三羧酸(1,3,5-H3BTC)的CuO/CeO2-135催化剂在相对较低的温度(T100%=100°C)下表现出优异的催化性能,CO转化率为100%,具有较宽的反应温度范围和优异的稳定性。优异的催化性能归因于1,3,5-H3BTC前体提供的结构改进和氧空位的促进作用。此外,进行了原位拉曼光谱,以验证氧空位对CO吸附和活化的动态作用,而原位DRIFTS分析揭示了CO-PROX反应中的关键中间体,阐明催化过程的机理方面。这项工作不仅证明了对CO优先氧化的有效CuO/CeO2催化剂的见解,同时也为MOF衍生催化剂的合成提供了一条可行的途径。