郑珂, 刘冰, 胥月兵, 刘小浩. 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[J]. 燃料化学学报(中英文), 2024, 52(9): 1214-1223. DOI: 10.1016/S1872-5813(24)60450-0
引用本文: 郑珂, 刘冰, 胥月兵, 刘小浩. 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[J]. 燃料化学学报(中英文), 2024, 52(9): 1214-1223. DOI: 10.1016/S1872-5813(24)60450-0
ZHENG Ke, LIU Bing, XU Yuebing, LIU Xiaohao. Effect of Rh loading on the selectivity to methanol and ethanol in the hydrogenation of CO2 over the Rh/CeO2 catalyst[J]. Journal of Fuel Chemistry and Technology, 2024, 52(9): 1214-1223. DOI: 10.1016/S1872-5813(24)60450-0
Citation: ZHENG Ke, LIU Bing, XU Yuebing, LIU Xiaohao. Effect of Rh loading on the selectivity to methanol and ethanol in the hydrogenation of CO2 over the Rh/CeO2 catalyst[J]. Journal of Fuel Chemistry and Technology, 2024, 52(9): 1214-1223. DOI: 10.1016/S1872-5813(24)60450-0

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

Effect of Rh loading on the selectivity to methanol and ethanol in the hydrogenation of CO2 over the Rh/CeO2 catalyst

  • 摘要: 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3.0 MPa、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。

     

    Abstract: 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.

     

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