Florou Alexandra, Bampos Georgios, Natsi Panagiota D, Kokka Aliki, Panagiotopoulou Paraskevi
Laboratory of Environmental Catalysis, School of Chemical and Environmental Engineering, Technical University of Crete, GR-73100 Chania, Greece.
Department of Chemical Engineering, University of Patras, GR-26504 Patras, Greece.
Nanomaterials (Basel). 2023 Dec 28;14(1):86. doi: 10.3390/nano14010086.
The CO-assisted oxidative dehydrogenation of propane (ODP) was investigated over titania based composite metal oxides, 10% MO-TiO (M: Zr, Ce, Ca, Cr, Ga). It was found that the surface basicity of composite metal oxides was significantly higher than that of bare TiO and varied in a manner which depended strongly on the nature of the MO modifier. The addition of metal oxides on the TiO surface resulted in a significant improvement of catalytic performance induced by a synergetic interaction between MO and TiO support. Propane conversion and propylene yield were strongly influenced by the nature of the metal oxide additive and were found to be superior for the CrO-TiO and GaO-TiO catalysts characterized by moderate basicity. The reducibility of the latter catalysts was significantly increased, contributing to the improved catalytic performance. This was also the case for the surface acidity of GaO-TiO which was found to be higher compared with CrO-TiO and TiO. A general trend was observed whereby catalytic performance increased significantly with decreasing the primary crystallite size of TiO. DRIFTS studies conducted under reaction conditions showed that the adsorption/activation of CO was favored on the surface of composite metal oxides. This may be induced by the improved surface basicity observed with the MO addition on the TiO surface. The GaO containing sample exhibited sufficient stability for about 30 h on stream, indicating that it is suitable for the production of propylene through ODP with CO reaction.
研究了基于二氧化钛的复合金属氧化物10%MO-TiO(M:Zr、Ce、Ca、Cr、Ga)上CO辅助的丙烷氧化脱氢反应(ODP)。发现复合金属氧化物的表面碱性显著高于纯TiO,且其变化方式强烈依赖于MO改性剂的性质。在TiO表面添加金属氧化物导致MO与TiO载体之间的协同相互作用显著提高了催化性能。丙烷转化率和丙烯产率受金属氧化物添加剂性质的强烈影响,发现对于具有中等碱性的CrO-TiO和GaO-TiO催化剂而言更为优异。后一种催化剂的还原性显著提高,有助于催化性能的改善。GaO-TiO的表面酸性也是如此,发现其比CrO-TiO和TiO更高。观察到一个普遍趋势,即催化性能随着TiO初级晶粒尺寸的减小而显著提高。在反应条件下进行的漫反射红外傅里叶变换光谱(DRIFTS)研究表明,复合金属氧化物表面有利于CO的吸附/活化。这可能是由于在TiO表面添加MO后观察到的表面碱性改善所致。含GaO的样品在约30小时的连续运行中表现出足够的稳定性,表明它适用于通过ODP与CO反应生产丙烯。