11Molybdenum carbide nanoparticles supported on carbon catalysts have been prepared 12 with a modified carbothermal reduction method. The soft carburization conditions of 13 this method allows the preparation of a nanoparticulate Mo2C even with high Mo 14 loading (50 wt%). The catalytic activity towards hydrogen evolution reaction was 15 analyzed both in an electrochemical cell at various pHs and in a laboratory-scale 16 electrolyser. These nanoparticles were found to be very active for catalyzing hydrogen 17 evolution reaction in acidic media and appeared to promote kinetics leaning towards the 18 Volmer-Heyrovský mechanism at low pH. Moreover, the Mo2C/C catalyst was shown 19 to be suitable for hydrogen production in the laboratory-scale electrolysis cell retaining 20 its performance during the four week durability experiment. Thus this study implies that 21 the investigated Mo2C/C electrocatalyst is a promising alternative for platinum as a 22 2 cathode material for electrolytic hydrogen production because of favorable kinetics and 23 stability. 24 25

Designing earth‐abundant element based efficient and durable electrocatalysts for hydrogen evolution reaction (HER) is attracting growing attention as the renewable electricity supply sector urgently needs sustainable methods for storing energy. Nitrogen functionalized carbon nanomaterials are an interesting electrocatalysts option because of their attractive electrical properties, excellent chemical stability and catalytic activity. Hence, this study reports the HER mechanism on nitrogen functionalized few‐walled carbon nanotubes (N‐FWCNT). With this earth‐abundant element based catalyst 250 mV overpotential is required to reach 10 mA cm−2 current density and so its HER activity is comparable to other non‐noble metal catalysts, and clearly among the highest previously reported for N‐FWCNTs. To gain fundament insight on their functioning, computational analysis has been carried out to verify the effect of nitrogen and to analyze the reaction mechanism. The reaction mechanism has also been analyzed experimentally with a pH series, and both the methods suggest that the HER proceeds via the Volmer‐Heyrovský mechanism. Overall hydrogen surface coverage on N‐FWCNT is also suggested to affect the HER rate. Interestingly, in the studied structure, carbons in vicinity of nitrogen atoms, but not directly bound to nitrogen, appear to promote the HER most actively. Furthermore, durability of N‐FWCNTs has been demonstrated by operating a full electrolyzer cell for five weeks.

No abstract

No abstract

No abstract