Convenient Synthesis of a Ru Catalyst Containing Single Atoms and Nanoparticles on Nitrogen-Doped Carbon with Superior Hydrogen Evolution Reaction Activity in a Wide pH Range

Abstract

Ruthenium, which is relatively cheap in precious metals, has become a popular alternative for a hydrogen evolution reaction (HER) catalyst because of its corrosion resistance and appropriate metal–H bond strength. Convenient synthesis and active site regulation are conducive to stimulating the excellent catalytic performance of Ru as much as possible. Herein, using the mature mesoporous nitrogen-doped carbon material as the support, the catalytic materials containing both single atom Ru and Ru nanoparticles were synthesized by impregnation using the solid-phase reduction method. The effect of reduction temperature on the dispersion state and electronic structure of Ru species has been fully studied using electronic and spectroscopic characterizations. The sample reduced at 300 °C has excellent HER activity with overpotentials of 10.8 and 53.8 mV to deliver 10 mA/cm2 in alkaline and acidic media, respectively, which is among the best activities in the reported results. Electrochemical impedance analysis shows that the reduction temperature has a great influence on the number of active sites and charge transfer impedance of the catalyst.

Lattice Strain and Schottky Junction Dual Regulation Boosts Ultrafine Ruthenium Nanoparticles Anchored on a N-Modified Carbon Catalyst for H2 Production

“…In particular, the mass activity was also calculated as an important indicator for evaluating the noble metal HER catalyst. As displayed in Figure S14, the Ru NPs/NC-900 catalyst exhibited obviously higher mass activity than that of the commercial 20 wt % Pt/C catalyst, indicating the superior practical application potential of Ru NPs/NC-900 . In addition to the HER activity, stability is another key factor to evaluate an electrocatalyst.…”

“…As displayed in Figure S14, the Ru NPs/NC-900 catalyst exhibited obviously higher mass activity than that of the commercial 20 wt % Pt/C catalyst, indicating the superior practical application potential of Ru NPs/NC-900. 50 In addition to the HER activity, stability is another key factor to evaluate an electrocatalyst. In Figures 3c and S15, Ru NPs/ NC-900 displayed no appreciable activity degradation after the long-term stability test.…”

Observation of a robust and active catalyst for hydrogen evolution under high current densities

“…The charge relaxation time is decreased from 0.05 to 0.03 s after activation, suggesting the improved HER transfer kinetics. Interestingly, we found that the charge relaxation time of our sample is even shorter than the state-of-the-art commercial Pt/C catalysts (0.62 s) and Ru single-atom catalysts (0.08 s) 66 . It is interesting to see a rapid relaxation process (10 −4 s) in the high-frequency (10 3 –10 4 Hz) regime, which is two orders of magnitude lower than the interfacial charge transfer process.…”

Interfacial Effect of CNT-Supported Ultrafine Ru Nanoclusters on Efficient Transfer Hydrogenation of Nitroaromatic Compounds

“…Moreover, the N 1s binding energy of Ru/CNT@CN is divided into four independent peaks, including pyridinic N (398.7 eV), pyrrolic N (400.0 eV), Ru−N (401.2 eV), and graphitic N (404.5 eV) (Figure 2d). 30,35 These data further prove the electronic transfer from Ru NCs to pyrrolic N and indicate that the Ru NCs with low surface electronic density might show high selectivity in the hydrogenation reaction of nitro compounds. 2.2.…”