Single-atom zinc catalyst for co-production of hydrogen and fine chemicals in soluble biomass solution

Abstract

Single-atom photocatalysts (SAPCs) have attracted great interests due to their remarkable atom utilization efficiency, excellent activity, and selectivity, yet no application in synchronous biorefinery and water splitting. Here, efficient SAPCs based on atomically dispersed Zn atoms on carbon nitride (named Zn−mCN) were produced. Experiments verified that Zn−mCN has widened adsorption range of visible-light and lowered ability of electron−hole recombination, leading to excellent photocatalytic redox activity for synchronous biorefinery and water splitting to co-produce lactic acid (selectivity up to 91.0%) and hydrogen (∼15898.8 ​μmol ​g⁻¹ ​h⁻¹). This system has excellent universality for small- molecule monosaccharides and macromolecular xylan. Poisoning experiments showed that h⁺, ¹O₂, ·O₂⁻ and ·OH can promote the simultaneous production of lactic acid and hydrogen. This work realized full utilization of whole redox reaction and provided a novel strategy for efficient and concomitant production of hydrogen and value-added chemicals from biomass-derived feedstocks aqueous solutions.