Plasmon-Enhanced Photocatalysis Coupling Electrocatalysis Steering Methanol Oxidation toward a CO-Free Dominant Pathway

Abstract

Methanol electro–oxidation reaction (MOR), as the anode reaction of direct methanol fuel cells, fundamentally determines the device efficiency. Coupling electrocatalysis with photocatalysis provides a promising yet challenging strategy to accelerate the MOR kinetics. Herein, we demonstrate that the localized surface plasmon resonance (LSPR) from Ag strengthens the photo-/electrocatalysis coupling process, leading to a dramatical decrease in the apparent activation energy and thus doubling MOR currents over Pt/Ag0.333V2O5 under illumination versus in dark. Mechanism investigations reveal that the MOR enhancement can be mainly attributed to the accelerated dehydrogenation of methanol on a negatively charged Pt surface facilitated by the photogenerated OHad on Ag0.333V2O5, leading to a COad-free dominant pathway, and the LSPR of Ag promotes the charge transfer in the coupling process. This study sheds light on the mechanism of plasmonic metals involved in the photo-/electrocatalysis coupling process and provides an avenue for designing highly efficient MOR photo/electrocatalysts.