Chinese researchers develop new methodology for ethanol production from sunlight
In China, a research team at Xi’an Jiaotong University, China, has constructed ultrathin porous cadmium sulfide (CdS) nanosheets decorated with two types of “dual-functional” sites: individual ruthenium atoms (Ru single atoms) and sulfur vacancies. This design, reported in Science Bulletin, enables highly efficient and selective photoreforming of ethanol under simulated sunlight.
Under light irradiation, the Ru single atoms act as electron traps, while the sulfur vacancies capture holes. This spatial separation prevents the electrons and holes from recombining, allowing them to participate in desired chemical reactions. Moreover, the dual sites work together to weaken the key bonds in ethanol, lowering the energy barrier for its dehydrogenation. As a result, the catalyst converts ethanol into hydrogen and acetaldehyde with exceptional efficiency. In the presence of a trace amount of hydrochloric acid, the acetaldehyde further condenses to form 1,1-diethoxyethane (DEE), a valuable solvent and intermediate for pharmaceutical synthesis—with 100% selectivity.
The optimized catalyst, Ru0.2-CdS, achieved a hydrogen evolution rate of 157.9 μmol/h, 81.5 times higher than that of pristine CdS. The apparent quantum efficiency at 400 nm reached 67.1%, meaning more than two-thirds of incident photons are effectively utilized. No byproducts such as carbon dioxide or light hydrocarbons were detected, and the liquid product DEE was obtained with full selectivity. The catalyst also showed excellent stability, maintaining its activity over seven consecutive cycles.
The strategy proved general. When applied to lactic acid photoreforming, the same catalyst achieved a 27.3-fold enhancement in hydrogen production and 93.3% selectivity for pyruvic acid, another valuable chemical.
Category: Research
