Electrocatalytic water splitting for hydrogen production plays a vital role in the development of new energy field, but there is still a lack of low-content precious metal or cost-effective non-noble metal catalysts for the hydrogen evolution reaction (HER). Therefore, how to develop the catalysts with a smaller amount of precious metal to achieve higher performance is still a major challenge. Herein, we have fabricated Ru–Ni 2 P@Ni(OH) 2 /NF-2 heterostructure by phosphating Ni(OH) 2 /NF and then anchoring Ru on the surface through wet chemical strategy. Benefiting from its optimal Δ G H∗ and synergistic effect , this Ru–Ni 2 P@Ni(OH) 2 /NF-2 catalyst shows superior electrocatalytic HER kinetics in alkaline electrolyte . A small overpotential of 31 mV is needed for this electrocatalyst to obtain the current densities of 10 mA cm −2 with remarkable durability over 24 h. This work provides a new strategy for the preparation of effective HER electrocatalyst with a low precious metal content.
Haodong Tang,Yao Wang,Wujian Zhang,Zongjian Liu,Lichun Li,Wenfeng Han,Ying Li
SmCeO x composite oxide with Sm 3+ occupying Ce 4+ site in CeO 2 crystal lattice , prepared via citric acid complexation method, was loaded with 2 w% Ru by impregnation method and the as-prepared catalyst was then evaluated for ammonia decomposition. The results show that the partial substitution of Ce 4+ by Sm 3+ produces a positive effect on the catalyst performance and SmCeO x supported Ru exhibits a much higher low-temperature catalytic activity for ammonia decomposition compared with other supports such as Sm 2 O 3 , CeO 2 , and a physical mixture of Sm 2 O 3 and CeO 2 . For example, the ammonia conversion is increased from 54.6% to 74.9% at a temperature of 400 °C and a space velocity of 3900 ml/g cat ·h when CeO 2 is replaced by Sm 0.4 Ce 0.6 O 1.8 . TEM and CO chemisorption investigations reveal that the excellent performance of Ru/SmCeO x catalyst is related to its high Ru dispersion. The results of BET, EPR and H 2 -TPR suggest that the partial substitution of Ce 4+ with Sm 3+ may induce the formation of oxygen vacancies and the high Ru dispersion can be attributed to the presence of large amount of single-electron trapped oxygen vacancies on the surface of SmCeO x , which have a strong interaction with Ru and thus Ru preferentially occupies the oxygen vacancies. This experimental observation is also supported by the DFT calculation result that Ru species adsorbed on the oxygen vacancy has a low adsorption energy .
Ammonia is one of the most important agricultural fertilizers and renewable energy carriers, and is also one of the most highly produced inorganic compounds in the world. The traditional industrial ammonia synthesis mainly uses the Haber–Bosch method, which consumes a large amount of fossil fuels and emits a lot of greenhouse gas. Thus, a more environmentally friendly method is needed for the production of ammonia. In this paper, we present a new electrocatalyst to produce NH3 under ambient conditions, which was obtained via the carbonization of Ru-dispersed ZIF-8. As a result, the catalyst could achieve a maximum NH3 production rate of about 16.68 μgNH3 h−1 mgcat.−1 at −0.4 V (vs. RHE) and a faradaic efficiency of 14.23% at −0.3 V (vs. RHE) at room temperature and ambient pressure in 0.1 M KOH. Also, the loading of Ru is only 16 wt%. Thus, this work provides a feasible method to design highly dispersed noble metal electrocatalysts for the nitrogen reduction reaction (NRR).
危险品化学品经营许可证（带存储）