Efficient photothermal alcohol dehydration over a plasmonic W18O49 nanostructure under visible-to-near-infrared irradiation

Abstract

Developing new techniques toward low-cost, high-efficiency, and environmental-friendly transformation of alcohol to hydrocarbon compounds via carbon–carbon coupling has been paid a lot of research attention. In this study, we report for the first time on photothermal alcohol dehydration over a plasmonic W18O49 nanostructure under visible-to-near-infrared (Vis−NIR) irradiation. In the case of methanol dehydration, dimethyl ether and ethylene are generated as the major products with a 75% of methanol conversion efficiency. The light source, especially the NIR part, plays an important role in activation of the target methanol molecules, favoring the photothermal catalysis for both the methanol conversion and ethylene selectivity. The methanol dehydration activity is also greatly improved with increasing the content of W5+ in the surface of W18O49. More importantly, the non-stoichiometric W18O49 catalyst can be self-remediated via the reduction of surface W6+ to W5+ by photoelectron and methanol. In addition to methanol dehydration, the W18O49 catalyst also exhibits an extremely high catalytic activity for photothermal ethanol dehydration with nearly 98% ethanol conversion and 100% ethylene selectivity under Vis−NIR irradiation. This work provides a new insight into the photothermal catalytic alcohol dehydration over plasmonic semiconductors.