Tunable hydrogen coverage on electron-deficient platinum nanoparticles for efficient hydrogenation reactions

Dissociation of active H species over the catalytic sites with the carbon-supported Pt metals as the mainstream catalysts is crucial to facilitate hydrogen donation and accelerate the hydrogen addition process in catalytic hydrogenation systems to produce polymers,pharmaceuticals,agrochemicals,fragrances,and biofuels at million-ton scale.Much attention has been paid to the design of the more active catalytic site to effectively adsorb and activate reactants and H_(2) molecules.At the same time,there is still a huge room to develop powerful strategies to accelerate the donation of acted H species to the reactants from the Pt surface further to boost the final catalytic efficiencies of Pt catalysts and depress the total Pt consumption.Herein,we present a new strategy for promoting the Pt-H bond dissociation by increasing surface hydrogen coverage on designed electron-deficient Pt nanoparticles.The electron deficiency of Pt nanoparticles has been successfully tuned by constructing a rectifying contact with an even“noble”boron-rich carbon support(Pt/BC).Theoretical and experimental results confirm the dominant role of the pronounced electron deficiencies of Pt nanoparticles in enhancing the H coverage for 2.3 times higher than that of neutral Pt nanoparticles,significantly boosting the Pt-H bond dissociation and thus the whole hydrogenation process as reflected by the extremely high turnover frequency(TOF)value of 388 h^(-1)at 30℃ and 10 bar H_(2) for phenol hydrogenation on the Pt/BC,outperforming the bench-marked catalysts by a factor of 9.

Accelerating the Activation of NO_(x)^(−)on Ru Nanoparticles for Ammonia Production by Tuning Their Electron Deficiency

Stable and portable ammonia(NH3)is a promising,low-cost,and environment-friendly medium for energy storage.How to achieve the rapid production of NH3 from reducing NO_(x)^(−)in aqueous systems and industrial wastewater via electrochemical methods remains the main challenge for practical application on a large scale.The corresponding electrocatalysts as the key materials in electrochemical devices suffer from low activity,especially in neutral systems.In this work,we successfully elevated the activity of the bench-mark Ru electrocatalysts to more than 30 times via construction of rectifying contact of Ru metals and noble carbons.We theoretically predicted and then rationally designed a new type of P-O rich carbon with large work functions as“noble”supports to attract a pronounced number of electrons from Ru metals at the rectifying interface.The resulting electron deficiency of Ru metals largely promotes the pre-adsorption and activation of NO_(x)^(−)anions,providing high Faradaic efficiencies(>96%)and record-high turnover frequency values for universal NO_(2)^(−)and NO_(3)^(−)reduction in neutral solution.