Abstract

The comparative study of the catalytic behavior of K-modified CoMoS₂-catalysts supported on Al₂O₃, carbon covered alumina (CCA) and graphene coated alumina (GCA containing 0.4, 1.2, and 1.7% of graphene) in synthesis gas and ethanol conversion (separately) to higher alcohols (HAS) and other oxygenates has been carried out. The supports and catalysts were characterized by N₂ adsorption-desorption isotherms, pyridine adsorption, SEM, EDX, and TEM. In HAS from syngas, the catalyst supported on GCA materials showed better catalytic performances than the catalysts supported on alumina and carbon coated alumina (Cat-GCA > Cat-CCA > Cat-Al₂O₃). The spectroscopic results have established that the homogenous uniform coating of alumina by graphene nanosheets follows the order: GCA1 (1.7%) > GCA2 (1.2%) > GCA3 (0.4%). The yield of ethanol has a positive correlation with graphene wt. % in GCA. In ethanol conversion, graphene attenuate the interaction of the support/active site KCoMoS₂ and with it its selectivity toward dehydrogenation/condensation reactions. The GCA1 supported catalyst exhibits low activity for the water–gas shift (WGS) reaction compared to its counterpart. Explanations of the observed phenomena have been suggested.

摘要

_{Al 2} O ₃、碳包覆氧化铝（CCA）和石墨烯包覆氧化铝（GCA含0.4%、1.2%和1.7%石墨烯）负载K改性CoMoS ₂催化剂在合成气和乙醇中催化行为的比较研究（分别）转化为高级醇（HAS）和其他含氧化合物。_{通过N 2}吸附-解吸等温线、吡啶吸附、SEM、EDX和TEM对载体和催化剂进行了表征。在合成气 HAS 中，GCA 材料负载的催化剂比氧化铝和碳包覆氧化铝负载的催化剂表现出更好的催化性能 (Cat-GCA > Cat-CCA > Cat-Al ₂ O ₃）。光谱结果表明，石墨烯纳米片均匀均匀地涂覆氧化铝遵循以下顺序：GCA1 (1.7%) > GCA2 (1.2%) > GCA3 (0.4%)。乙醇的产率与石墨烯重量呈正相关。占 GCA 的百分比。_{在乙醇转化中，石墨烯减弱了载体/活性位点 KCoMoS 2}的相互作用及其对脱氢/缩合反应的选择性。与同类催化剂相比，GCA1 负载型催化剂在水煤气变换 (WGS) 反应中表现出较低的活性。已经提出了对观察到的现象的解释。