Zero-emission multivalorization of light alcohols with self-separable pure H2 fuel

Abstract

To reach Paris Agreement's target of 1.5 °C global temperature increase by 2100, low emission strategies are crucial. In synthetic chemistry, the phototransformation of light alcohols (methanol, ethanol and iso-propanol) into hydrogen fuel and chemicals promises high potential utility value for industry. However, this process is often practiced using promoters (i.e. water, acid or base), with and several issues remained unsolved, e.g. water promoter induce CO2 emission; acid/base promoters restrict catalyst selection, and lead to complicated product purification and cost increase. In this work, we report solar-driven promoter-free multivalorization of light alcohols into self-separable hydrogen gas/fuel and liquid chemicals without COx emission based on the two-dimensional (2D) SnS/g-C3N4 heterojunction. The hydrogen production efficiency reaches 1.27 mmol.g−1. h−1 with ∼ 95 % recoverability. The process reduction occurs via a sequence of redox reactions, combination and disproportionation, as confirmed from experimental and product analysis. This work demonstrates the effectiveness of 2D heterojunctions for promoter-free, zero-emission alcohol phototransformations.