Hydrogen generation from toxic formaldehyde catalyzed by low-cost Pd-Sn alloy driven by visible light

Noble co-catalysts are efficient for photocatalytic hydrogen generation from formaldehyde, but their low-abundance and high-cost limit their scale-up applications. Alloying the second metal with noble metals offers available way to decrease their usage and consumption while enhances their catalytic activity. Among the potential candidates, Sn is a high abundance element on the Earth. In this work, a new high active low-cost cocatalyst for hydrogen evolution from formaldehyde via alloying of Pd with Sn has been developed. Under optimized condition, the hydrogen evolution rate reached up to 530.07 μmol•h−1 under visible light irradiation. By taking advantage of optimized adsorption nature of active sites on alloy cocatalyst, more efficient charge transfer and separation, the prolonged the lifetime of photogenerated electrons have been achieved. More interestingly, it has been found that the trace amount of oxygen can promote conversion toxic formaldehyde into hydrogen by inhibition of the reverse recombination of hydrogen and oxygen.