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Catalysts with amorphous structures have shown excellent performance in electrocatalytic water oxidation, but it remains a challenge to prepare efficient catalysts using simple methods while maintaining high yields. Herein, amorphous Fe x Co y W z oxides nanoparticles were prepared by a one-step co-precipitation method, and the Fe content was optimized to ensure efficient water oxidation. The prepared Fe 0.05 Co 0.09 W 0.61 O 0.25 had the best OER performance with a yield of 95.6% when the Co and Fe feeding ratio was 2:1. The Fe 0.05 Co 0.09 W 0.61 O 0.25 possessed an overpotential of 267 mV at 10 mA cm−2 with a small Tafel slope of 39.4 mV dec−1. The activation energy at 1.5 V is only 49.4 kJ mol−1, and Faraday efficiency is close to 100%. The water oxidation performance of the two-electrode test shows that the voltages at 10 mA cm−2 are only 1.50 V. In addition, it still maintained high activity after 72 h of chronoamperometry test, which exhibits excellent water oxidation performance among similar non-precious transition metal catalysts. Therefore, the present work provides a simple and easy way to prepare high-activity and high-yield transition metal amorphous electrocatalysts. [Display omitted] • The simple method successfully prepared high performance amorphous Fe 0.05 Co 0.09 W 0.61 O 0.25. • Fe modulates the electronic configuration and morphology of CoWO 4. • The optimal ratio of Fe doping into CoWO 4 is regulated. • Co acts as the main catalytic site in the OER process instead of Fe. [ABSTRACT FROM AUTHOR]

Co 3 O 4 is an excellent catalyst for the thermal decomposition of ammonium perchlorate (AP) due to its spinel structure and more Co3+ as catalytically active sites. In this work, MCo 2 O 4 (M=Fe, Cu, Ni and Zn) with different Co species substituted with transition metal ion were prepared using triblock copolymer F127 as soft template by simple solvothermal and subsequent heat treatment. The porous MCo 2 O 4 samples have higher Co3+ / Co2+ ratio than Co 3 O 4 , and exhibits better catalytic performance for thermal decomposition of AP. Especially with the addition of FeCo 2 O 4 , the high decomposition temperature (HDT) of AP decreases by an amazing 196.25 °C, showing the most excellent catalytic performance. The activation energy (E a) decreases from 290.19 kJ·mol−1 for pure AP to 203.05 kJ·mol−1, while the reaction rate (k) increases from 0.499 s−1 to 1.699 s−1. Based on the electron transfer theory, the catalytic mechanism and active site of porous MCo 2 O 4 series cobaltate materials are discussed. The results show that the porous FeCo 2 O 4 not only has highest specific surface, but also has the highest Co3+/ Co2+ ratio, which suggest that the Co3+ on octahedral coordination sites is known as the catalytic active site for AP thermal decomposition. [Display omitted] • Ordered nanoporous MCo 2 O 4 (M=Fe, Cu, Ni and Zn) were successfully syntesized and substituted for the Co in Co 3 O 4. • The high Co3+ / Co2+ ratio and specific surface area of FeCo 2 O 4 provide higher catalytic activity and sites. • The kinetic parameters of AP thermal decomposition have been better optimized after adding porous FeCo 2 O 4. • The catalytic mechanism of porous FeCo 2 O 4 for thermal decomposition of AP is proposed. [ABSTRACT FROM AUTHOR]