Photocatalytic conversion of biomass into syngas offers a sustainable pathway to utilize renewable carbon sources and solar energy under ambient conditions. However, the efficiency of this process is often limited by inefficient electron-proton transfer during C–C bond cleavage. This study presents a novel strategy to simultaneously enhance both electron transfer (ET) and proton transfer (PT) by introducing surface sulfate ions ([SO₄]) onto CdS nanorods through oxygen plasma treatment. The resulting [SO₄]/CdS catalyst demonstrates significantly improved performance in photocatalytic reforming of glycerol and other biopolyols into syngas (CO + H₂) under visible light irradiation.
The surface sulfate ion acts as a bifunctional agent: it serves as a proton acceptor due to its strong hydrogen-bonding capability, thereby facilitating PT by minimizing the proton transfer distance and enhancing vibrational wave function overlap. Simultaneously, theoretical calculations reveal that the introduction of [SO₄] increases the work function of CdS and raises the valence band (VB) maximum, resulting in higher oxidation potential of photoinduced holes—thus promoting ET.61849-14-7 Formula Density functional theory (DFT) simulations confirm that the sulfate group preferentially interacts with hydroxyl groups of substrates like methanol, forming a stable O···H hydrogen bond (1.79 Å), which weakens the O–H bond and lowers the activation barrier for hydrogen abstraction.
Experimental results show that [SO₄]/CdS-30 min exhibits a CO generation rate of 0.31 mmol g⁻¹ h⁻¹—nearly nine times higher than pristine CdS (0.034 mmol g⁻¹ h⁻¹)—and a H₂ production rate of 0.05 mmol g⁻¹ h⁻¹, fourfold greater than the control. The system operates at room temperature with no CO₂ detected, confirming selective syngas formation. A wide range of biopolyols—including glucose, fructose, sucrose, lactose, maltose, xylose, inulin, and starch—are efficiently converted into syngas with high selectivity. Stability tests indicate that the catalyst remains active for up to 150 hours without significant degradation.
Mechanistic studies reveal that glycerol undergoes sequential dehydrogenation and decarbonylation steps via a proton-coupled electron transfer (PCET) pathway.635702-64-6 References Key intermediates such as glyceraldehyde, formaldehyde, and hydroxyacetone are identified, supporting a reaction network where vicinal diols and carbonyl-containing compounds are more reactive.PMID:30000266 Radical trapping experiments confirm the involvement of acyl radicals in C–C bond cleavage. Furthermore, immobilized CdSO₄/CdS shows inferior activity and poor stability, indicating that the catalytic enhancement stems specifically from dispersed surface [SO₄], not bulk sulfate phases.
This work establishes the pivotal role of surface sulfate ions in enabling efficient PCET processes in photocatalysis. By simultaneously optimizing ET and PT through rational surface engineering, this approach provides a powerful and scalable method to boost the efficiency of solar-driven biomass valorization.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
