Wettability Engineering of Solar Methanol Synthesis
Zhe Lu, Yangfan Xu, Zeshu Zhang, Junchuan Sun, Xue Ding, Wei Sun, Wenguang Tu, Yong Zhou, Yingfang Yao, Geoffrey A. Ozin, Lu Wang, Zhigang Zou
Abstract
Engineering the wettability of surfaces with hydrophobic organics has myriad applications in heterogeneous catalysis and the large-scale chemical industry; however, the mechanisms behind may surpass the proverbial hydrophobic kinetic benefits. Herein, the well-studied In 2 O 3 methanol synthesis photocatalyst has been used as an archetype platform for a hydrophobic treatment to enhance its performance. With this strategy, the modified samples facilitated the tuning of a wide range of methanol production rates and selectivity, which were optimized at 1436 μmol g cat –1 h –1 and 61%, respectively. Based on in situ DRIFTS and temperature-programmed desorption-mass spectrometry, the surface-decorated alkylsilane coating on In 2 O 3 not only kinetically enhanced the methanol synthesis by repelling the produced polar molecules but also donated surface active H to facilitate the subsequent hydrogenation reaction. Such a wettability design strategy seems to have universal applicability, judged by its success with other CO 2 hydrogenation catalysts, including Fe 2 O 3, CeO 2, ZrO 2, and Co 3 O 4 . Based on the discovered kinetic and mechanistic benefits, the enhanced hydrogenation ability enabled by hydrophobic alkyl groups unleashes the potential of the surface organic chemistry modification strategy for other important catalytic hydrogenation reactions.