Zhongzhe Wei,Zijiang Zhao,Jing Wang,Qiang Zhou,Chenxia Zhao,Zihao Yao,Jianguo Wang
The limited reserves and sluggish H2O dissociation process of Pt necessitate the development of low-cost catalysts with enhanced catalytic performance in the alkaline hydrogen evolution reaction. Here, Ru nanoparticles supported on oxygen-deficient TiO2@carbon hybrids (Ru/TiO2-VO@C) were efficiently fabricated via one-pot carburization of RuCl3, TiO2(B) and melamine. The melamine additive assists the formation of oxygen vacancies (VO) and Ru0 and introduces a beneficial carbon dopant. Ru/TiO2-VO@C features a remarkably enhanced alkaline HER performance with an overpotential of only 64 mV to attain a current density of 10 mA cm−2. This satisfactory catalytic performance originates from the strong electronic interaction between Ru and TiO2-VO and the synergistic interplay between TiO2-VO and the carbon dopant. This synergistic cooperation improves the conductivity, promotes the dissociation of H2O and optimizes the hydrogen adsorption free energy. This study opens an avenue for the reasonable design of multi-component nanostructures and gives in-depth insights into the alkaline HER mechanism.
Zhongzhe Wei,Zihao Yao,Qiang Zhou,Guilin Zhuang,Xing Zhong,Shengwei Deng,Xiaonian Li,Jianguo Wang
The reaction/diffusion kinetics are fundamentally determined by the electronic properties of supported Pd catalysts and further govern the catalytic activity and selectivity in the partial hydrogenation of alkynes. However, how the electronic metal–support interactions and the tradeoff between reaction and diffusion affect the catalytic performance still remain elusive. Here, the optimized catalyst Pd supported on carbon decorated with oxygen-deficient TiO2(Pd/TiO2-VO@C) features a remarkable enhancement in performance for semihydrogenation of 2-methyl-3-butyn-2-ol with a TOF 31-fold higher than that of Lindlar catalyst. The improved performance of Pd/TiO2-VO@C benefits from the fact that TiO2-VO@C subtly modulates the electronic properties of Pd, and an appropriate amount of TiO2-VO allows a decrease in the reaction barrier and C promotes the diffusion ability of the catalyst, achieving the balance between reaction and diffusion. By using microkinetic modeling, the reactivity difference of various catalysts is quantitatively predicted and the calculated turnover frequency volcano curve is rationalized as a function of reaction barrier and diffusion ability, which agrees well with the experimental results. The quantitative regulation of catalytic performance by tuning the support properties is a general strategy, which provides a basis to design robust catalysts for diverse reactions.
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