Coupling Cross-Dimensional Ru 1 –Ru n Sites in Confined Nanoislands to Overcome the Limitation of Coadsorption and Diffusion in Tandem Reactions

作者：Huifang Wu, Qian Wang, Yang Zhao, Zhexi Gao, Yanjun Lin, Lirong Zheng, Dianqing Li, Junting Feng · 发表于：ACS Catalysis · 年份：2024 · DOI：10.1021/acscatal.3c05112 · 被引用次数：13 · 研究领域：Nanomaterials for catalytic reactions、Ammonia Synthesis and Nitrogen Reduction、Catalytic Processes in Materials Science

Integrating different reaction sites offers prospects to address the difficulties in single-atom catalysis and helps overcome the limitation of scaling relations for coadsorption. Here, we coupled different dimensional Ru 1 and Ru n active sites on confined Co nanoislands for the reductive amination of 5-hydroxymethylfurfural (5-HMF) to 5-aminomethyl-2-furanyl alcohol (AMF), constrained by the disequilibrium in the adsorption of NH 3 /H 2 . Ru clusters trigger an ensemble effect by multipoint-bonding with NH 3 and thus become more conductive to dissociate NH 3 to NH 2 * than Ru 1 both thermodynamically and kinetically, which releases Ru 1 for activating H 2 to enhance local H* coverage. Furthermore, intimate active sites in confined spaces enable the timely diffusion of NH 2 */H* to react with imine intermediates adsorbed on nanoislands in the di-σ C,N configuration. With confined cross-dimensional sites overcoming the limitations of competitive adsorption and diffusion, Ru 1+ n @Co/MMO exhibits a record-high AMF production rate (295 g·g Ru –1 h –1 ) without the requirement of high NH 3 /H 2 feeding, and it exhibits a mass specific activity even higher than that of single-atom Ru 1 @Co/MMO.