Ultrabroadband plasmon driving selective photoreforming of methanol under ambient conditions.

Abstract

Liquid methanol has the potential to be the hydrogen energy carrier and storage medium for the future green economy. However, there are still many challenges before zero-emission, affordable molecular H₂ can be extracted from methanol with high performance. Here, we present noble-metal-free Cu-WC/W plasmonic nanohybrids which exhibit unsurpassed solar H₂ extraction efficiency from pure methanol of 2,176.7 µmol g^-1 h^-1 at room temperature and normal pressure. Macro-to-micro experiments and simulations unveil that local reaction microenvironments are generated by the coperturbation of WC/W's lattice strain and infrared-plasmonic electric field. It enables spontaneous but selective zero-emission reaction pathways. Such microenvironments are found to be highly cooperative with solar-broadband-plasmon-excited charge carriers flowing from Cu to WC surfaces for efficient stable CH₃OH plasmonic reforming with C₃-dominated liquid products and 100% selective gaseous H₂. Such high efficiency, without any CO_x emission, can be sustained for over a thousand-hour operation without obvious degradation.