The electrochemical oxygen reduction reaction in acidic media offers an attractive route for direct hydrogen peroxide (H 2 O 2 ) generation and on-site applications. Unfortunately there is still a lack of cost-effective electrocatalysts with high catalytic performance. Here, we theoretically designed and experimentally demonstrated that a cobalt single-atom catalyst (Co SAC) anchored in nitrogendoped graphene, with optimized adsorption energy of the *OOH intermediate, exhibited a high H 2 O 2 production rate, which even slightly outperformed the state-of-the-art noble-metal-based electrocatalysts. The kinetic current of H 2 O 2 production over Co SAC could reach 1 mA=cm 2 disk at 0.6 V versus reversible hydrogen electrode in 0.1 M HClO 4 with H 2 O 2 faraday efficiency > 90%, and these performance measures could be sustained for 10 h without decay. Further kinetic analysis and operando X-ray absorption study combined with density functional theory (DFT) calculation demonstrated that the nitrogen-coordinated single Co atom was the active site and the reaction was rate-limited by the first electron transfer step.

Breaking long-range order in iridium oxide by alkali ion for efficient water oxidation

A bifunctional catalyst was designed to directly and selectively hydrogenate CO2 to ethylene and propene with a high selectivity of 80–90% in hydrocarbons by combining the synthesis of methanol and methanol-to-olefins processes.

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We report the preparation and characterization of Ni nanoparticles supported on barium hexaaluminate (BHA) as CO methanation catalysts for the production of synthetic natural gas (SNG). BHA with a high thermal stability was synthesized by a coprecipitation method using aluminum nitrate, barium nitrate, and ammonium carbonate as the precursors. The Ni catalysts supported on the BHA support (Ni/BHA) were prepared by an impregnation method. X-ray diffraction, nitrogen adsorption, transmission electron microscopy, thermogravimetric analysis, H2 temperature-programmed reduction, O2 temperature-programmed oxidation, NH3 temperature-programmed desorption, and X-ray photoelectron spectroscopy are used to characterize the samples. The CO methanation reaction was carried out at pressures of 0.1 and 3.0 MPa, weight hourly space velocities (WHSVs) of 30 000, 120 000, and 240 000 mL·g–1·h–1, with a H2/CO feed ratio of 3, and in the temperature range 300–600 °C. The results show that although the BHA support has a relatively low surface area, Ni/BHA catalysts displayed much higher activity than Al2O3-supported Ni catalysts (Ni/Al2O3) with a similar level of NiO loading even after high temperature hydrothermal treatment. Nearly 100% CO conversion and 90% CH4 yield were achieved over Ni/BHA (NiO, 10 wt %) at 400 °C, 3.0 MPa, and a WHSV of 30 000 mL·g–1·h–1. Long time testing indicates that, compared to Ni/Al2O3 catalyst, Ni/BHA is more stable and is highly resistant to carbon deposition. The superior catalytic performance of the Ni/BHA catalyst is probably related to the relatively larger Ni particle size (20–40 nm), the high thermal stability of BHA support with nonacidic nature, and moderate Ni–BHA interaction. The work demonstrates BHA would be a promising alternative support for the efficient Ni catalysts to SNG production.