is often required with minimal overpotential and fast kinetics. [12] At present, platinum (Pt) is commonly regarded as the most active catalyst toward HER because of its high exchange current density and small Tafel slope. [13][14][15] However, the high cost, scarcity and low stability of Pt metal in non-acidic media hindered their application in practical large-scale H 2 production. [16][17][18] Accordingly, it is highly desirable to develop effective, durable, inexpensive, and readily available catalysts that could work well for HER regardless of electrolyte pH values.Earth-abundant transition metal compounds, such as metal phosphates (MP x ) and metal oxides (MO x ), have been extensively investigated to develop cost-effective catalysts for HER. [19][20][21][22][23][24] However, the catalytic performance of these electrocatalysts are still far from comparable to commercial Pt/C, especially under alkaline or neutral conditions. [25,26] Recently, Ru-based materials attract great attention as advanced substitutes for HER electrocatalysis due to their relatively low cost (≈4% of Pt), high activity and excellent stability. [27][28][29] Many efforts have been made in this regard in recent years, ruthenium phosphides (RuP x ) compounds were proved to have superior HER catalytic performance that could be comparable with commercial Pt/C catalysts from both theoretical calculations and experimental points. [30][31][32] As reported by Mu et al. that RuP 2 nanoparticles embedded into a N, P codoped carbon (RuP 2 @NPC) could be employed as a catalyst
Searching for Pt-like activity, stable and economic electrocatalysts that can function at various pH values for the hydrogen evolution reaction (HER) is under increasing interest for the scientific community as H2 is a very promising energy carrier with great potential development value for renewable energy conversion. Herein, a unique self-supported heterostructure of RuO 2 -RuP 2 /Ru on the N, P co-doped carbon matrix (Ru-HMT-MP-7) is demonstrated, which is derived from HMT-based coordination polymers as superior pH-universal electrocatalysts. In the strategy, pyrolysis and phosphating processes are simultaneously proceeded that can produce the unique heterostructure containing three phases of RuO 2 , RuP 2, and Ru, at the same time the generated RuO 2 -RuP 2 /Ru can be highly dispersed on the self-assembly N, P co-doped carbon substrates. The resulting heterostructure Ru-HMT-MP-7 exhibits excellent activity superior to that of benchmark Pt/C with low overpotentials at 10 mA cm −2 (33 mV for 1.0 M KOH, 29 mV for 0.5 M H 2 SO 4 and 86 mV for 1.0 M PBS) and long-term electrocatalysis durability toward HER at various pH values. The rational construction strategy paves a novel avenue for obtaining superior pH-universal catalysts for electrochemical energy storage and conversion.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.202105168.