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

Plasmonic urchin-like W18O49 nanostructure exhibits efficient photothermal catalytic alcohol dehydration with nearly 100% selectivity for ethylene under visible-to-near infrared irradiation. [Display omitted] •Photothermal alcohol dehydration realized over a plasmonic urchin-like W18O49 nanostructure;•Efficient alcohol conversion with ∼ 100% selectivity for ethylene under Vis − NIR irradiation;•Increased W5+ concentration favors the photothermal alcohol dehydration;•Light irradiation enhances activation of the target alcohol molecules;•Self-remediation of W18O49 via the reduction of W6+ to W5+ by photoelectron and methanol. 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.