等离子体对合成低碳含氧化合物用铑基催化剂的影响

Effect of Glow Discharge Plasma on Rhodium-Based Catalyst for Oxygenates Synthesis

以辉光放电等离子体为促进手段制备了铑基催化剂,进行了XRD、XPS、H2-TPR、H2-TPD及CO-TPD表征,并以CO加氢合成含氧化合物为模型反应考察了其催化性能。表征结果显示,等离子体处理后,催化剂活性组分平均粒径减小,分散度提高,并发生了活性组分的表面富集,同时活性组分与助剂的相互作用发生改变,催化剂的还原性能和吸附性能得到了提高。反应结果表明,经等离子体促进后,催化剂的CO加氢活性显著提高,转化率最高提高了78.62%,含氧化合物的时空产率提高了51.96%,同时烃类选择性有所增加。在产物分布方面,随等离子体处理强度加大,甲醇、乙醇选择性升高,乙醛选择性降低。

The rhodium-based catalysts were prepared by impregnation, treated with glow discharge plasma, characterized by XRD, XPS, H2-TPR, H2-TPD and CO-TPD, and tested in oxygenate synthesis via CO hydrogenation. Based on the characterization results, plasma treatment endowed the samples with lower particle size, higher dispersion of active components, and an enrichment of active components on surface as well. In results, the reducibility and adsorption properties were modified. The reaction results suggested that reaction activity improved remarkably： the conversion of CO and the yield of oxygenates increased at most by 78.62 % and 51.96 %, respectively, while the selectivity of ethanol and methanol enhanced.