Surface chemistry connecting heterogeneous catalysis, photocatalysis and plasmonic catalysis

Chemical reactions catalyzed by solid catalysts have recently expanded rapidly from traditional heterogeneous catalytic reactions to photocatalytic reactions and further to plasmonic-catalytic reactions, however, the fundamental understanding of the commonalities and differences among heterogeneous catalysis, photocatalysis and plasmonic catalysis is not well established. Adsorption/reactions/desorption on solid catalyst surfaces commonly occur during these catalytic processes, thus surface chemistry of solid catalysts can be taken to bridge the fundamental understanding among heterogeneous catalysis, photocatalysis and plasmonic catalysis.

Regulating Electronic Status of Platinum Nanoparticles by Metal-Organic Frameworks for Selective Catalysis

Selective hydrogenation of alkynes to alkenes remains challenging in the field of catalysis due to the ease of over-hydrogenated of alkynes to alkanes.Favorably,the incorporation of metal nanoparticles(MNPs)into metal-organic frameworks(MOFs)provides an opportunity to adjust the surface electronic properties of MNPs for selective hydrogenation of alkynes.Herein,we used differentmetal-O clusters of MOFs to regulate the electronic status of platinum nanoparticles(Pt NPs)toward overhydrogenation,semihydrogenation,and unhydrogenation of phenylacetylene.Specifically,Pt/Fe-O cluster-based MOFs are found to reduce the electronic density on Pt NPs and inhibit the overhydrogenation of styrene,leading to an 80%increase in selectivity toward a semihydrogenation product(styrene).Meanwhile,Cu-O cluster-based MOFs generate high oxidation states of Pt NPs and release Cu^(2+)ions,which worked together to deactivate Pt NPs in the hydrogenation reaction entirely.Thus,our studies illustrate the critical role of metal-O clusters in governing chemical environments within MOFs for the precise control of selective hydrogenation of alkynes,thereby,offering appealing opportunities for designing MNPs/MOFs catalysts to prompt a variety of reactions.

The effect of surface electronic structures of Au/TiO_2 on sonophotochemical reactions

Sonophotocatalysis combines ultrasonic and light irradiations to drastically boost the chemical reaction rate and has attracted many interests for its potential applications in the environmental remediation and protection. However, it still remains unclear whether the light irradiation could couple with the ultrasound to prompt the sonophotocatalytic process. Here, we selectively excited the TiO2 and Au to manipulate the electronic structures of Au/TiO2 and studied their influence in sonophotocatalytic water（H2 O） reduction. Surprisingly, no significant increase of the hydrogen（H2） production rate was observed under either the UV light irradiation or the visible light irradiation, suggesting that the change in electronic structures of Au/TiO2 does not prompt the generation of free radicals under sonication and the reaction is dominated by the recovery of active sites through ultrasound. Our findings established an indepth understanding of the origin of the enhanced catalytic activity in sonophotocatalysis.