Rh/CeO2催化剂中Rh的负载量对其CO2加氢生成甲醇和乙醇产物选择性的影响OA北大核心CSTPCD
Effect of Rh loading on the selectivity to methanol and ethanol in the hydrogenation of CO2 over the Rh/CeO2 catalyst
将CO2捕获并通过加氢转化为醇类等高值化学品是实现CO2减排和碳资源循环利用的重要途径之一.本文对Rh/CeO2催化剂在CO2加氢反应中的性能进行了研究,并结合XRD、Raman、H2-TPR、CO2-TPD、CO-DRIFTS和XPS等表征方法,揭示了 Rh负载量(0.1%-2.0%)对其CO2加氢活性和产物选择性的影响.结果表明,在3.0MPa、250℃的反应条件下,Rh负载量为0.1%时Rh/CeO2催化剂上CO2加氢产物以乙醇为主.随着Rh含量的增加,CO2转化率增加,但乙醇选择性降低;当Rh负载量为2.0%时,产物以甲醇为主.对于Rh负载量不同的催化剂上的CO2加氢反应,其产物选择性的差异与催化剂中Rh的存在形式和电子性质有关;原子分散的Rh+有利于稳定CO*,CO*与CH3*进行C-C偶联形成乙醇,而金属态的Rh团簇则容易促成CO*加氢生成甲醇.
The capture and hydrogenation of CO2 into high-value chemicals such as alcohols is one of the important ways to reduce CO2 emission and achieve carbon resource recycling.In this work,the catalytic performance of Rh/CeO2 catalyst in the CO2 hydrogenation was investigated;with the help of various characterization methods including XRD,Raman,H2-TPR,CO2-TPD,CO-DRIFTS and XPS,the influence of Rh loading(0.1%-2.0%)on the catalytic activity of Rh/CeO2 and product selectivity in the CO2 hydrogenation was revealed.The results indicate that for the hydrogenation of CO2 at 250 ℃ and 3.0 MPa over the Rh/CeO2 catalysts,ethanol is the major product at a low Rh loading of 0.1%.With the increase of Rh loading,the conversion of CO2 increases,but accompanied by a decrease in the selectivity to ethanol;when the Rh loading reaches 2.0%,the main product turns to be methanol.It seems that the difference of various Rh/CeO2 catalysts with different Rh loadings in the product selectivity for the CO2 hydrogenation is ascribed to their difference in the structural and electronic properties of Rh;atomically dispersed Rh species favor the stabilization of CO*and its subsequent C-C coupling with CH3*to form ethanol,whereas metallic Rh clusters facilitate the hydrogenation of CO*to produce methanol.
郑珂;刘冰;胥月兵;刘小浩
江南大学化学与材料工程学院,江苏无锡 214122
化学
CO2加氢甲醇乙醇氧空位Rh单原子Rh团簇
CO2 hydrogenationmethanolethanoloxygen vacanciessingle Rh atomRh cluster
《燃料化学学报(中英文)》 2024 (009)
1214-1223 / 10
The project was supported by the National Key Research and Development program of China(2023YFB4103201)and the National Natural Science Foundation of China(22379053).国家重点研发计划(2023YFB4103201)和国家自然科学基金(22379053)资助
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