The highly efficient electrochemical hydrogen evolution reaction (HER) provides a promising way to solve energy and environment problems. In this work, various transition metals (Fe, Co, Ni, Cu, Ag, and Pt) were selected to support on molybdenum carbides by a simple organic-inorganic precursor carburization process. X-ray diffraction (XRD) analysis results indicated that the β-Mo2C phase was formed in all metal-doped samples. X-ray photoelectron spectroscopy analysis indicated that the binding energy of Mo2+species (Mo2C) shifted to a lower value after metal was doped on the molybdenum carbide surface. Comparing with pure β-Mo2C, the electrocatalytic activity for HER was improved by transition metal doping on the surface. Remarkably, the catalytic activity improvement was more obvious when Pt was doped on molybdenum carbide (2% Pt-Mo2C). The 2% Pt-Mo2C required a η10of 79 mV, and outperformed that of pure β-Mo2C (η10= 410 mV) and other transition metal doped molybdenum carbides, with a small Tafel slope (55 mV/dec) and a low onset overpotential (32 mV) in 0.5 M H2SO4. Also, the 2% Pt-Mo2C catalyst demonstrated a high stability for the HER in 0.5 M H2SO4. This work highlights a feasible strategy to explore efficient electrocatalysts with low cost via engineering on the composition and nanostructure.Keywords:hydrogen evolution reaction;nano-molybdenum-carbide;electro-catalysis;transition metal
Bao Tong,Hu Lele,Dai Jing,Chen Ke,Tan Tianlong,Sun Zhiyuan,Wang Jue,Zhang Qinfang
The
practical application of the hydrogen evolution reaction (HER)
in water electrolysis is severely hindered by the high cost, high
Pt loading, insufficient durability, and agglomeration tendency of
noble-metal nanoparticles. Despite numerous recent strategies, their
overall performance remains unsatisfactory. Herein, we report a Pt/Mo 2 C composite catalyst with tunable cluster size and intimately
coupled interfaces, precisely fabricated by a cluster beam deposition
(CBD) strategy. The optimized catalyst delivers overpotentials of
only 47 mV in acidic media and 228 mV in alkaline media at a current
density of 10 mA cm –2 . Remarkably, it exhibits outstanding
long-term stability (110 h) under acidic conditions, along with significantly
improved Pt utilization. The catalyst achieves a high mass activity
of 43.9 A mg pt –1 at an overpotential
of 50 mV, outperforming many benchmark Pt-based catalysts. Comprehensive
characterizations reveal pronounced interfacial electron transfer
from Pt to Mo 2 C, which optimizes the d-band center of Pt
and the adsorption energy of hydrogen intermediates. Furthermore,
particle agglomeration and surface passivation are effectively suppressed,
accelerating charge transfer and hydrogen desorption kinetics. This
work presents a strategy for the rational fabrication of metal clusters
with precise size control and offers a paradigm for designing noble
metal/transition metal carbide hybrid electrocatalysts.
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