Shape Effect of Pd-Promoted Ga2O3 Nanocatalysts for Methanol Synthesis by CO2 Hydrogenation

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• 作者：Jin Qu ; Xiwen Zhou ; Feng Xu ; Xue-Qing Gong ; Shik Chi Edman Tsang
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：October 23, 2014
• 年：2014
• 卷：118
• 期：42
• 页码：24452-24466
• 全文大小：832K
• ISSN：1932-7455

文摘

In this paper, we present a new approach to investigate metal鈥搒upport interaction in catalysis. First, we have carried out a controlled growth of two semiconductive Ga₂O₃ nanocrystals in distinctive shapes, namely, plate and rod with the majority of their surfaces covered with polar and nonpolar facets, respectively. We have then placed the same contents of Pd on these nanocrystals and carried out a systematic testing and characterization for methanol synthesis from CO₂ hydrogenation under industrial applicable conditions. It is found that a low indexed (002) polar Ga₂O₃ surface is highly unstable, which gives oxygen defects and mobile electrons in the conduction band more readily than those nonpolar (111) and (110) surfaces. A significantly strong metal鈥搒upport interaction between the (002) polar Ga₂O₃ surface and Pd was determined, and it gave rise to higher metal dispersion and facilitated electron transfer between them, leading to the formation of PdGa_x. This renders such composite nanocatalysts active for methanol production.