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How to overcome the bottleneck of Pt–based catalysts is a research focus in the field of energy conversion, and the combination of metal oxide with Pt–based catalysts is a promising strategy to avoid platinum aggregation and introduce novel photosensitivity into traditional Pt catalysts by virtue of the photosensitivity of metal oxide semiconductors. In this work, Pt–MoOx/graphene (S) (simplified as Pt–MoOx/GN (S)) was synthesized by a solid–phase reaction with Na2MoO4 as the Mo precursor, in which Na2MoO4 was partially reduced to MoO2, leading to the formation of MoOx in the composite. The integration of MoOx with Pt results in the uniform dispersion of Pt nanoparticles. Electrochemical tests reveal that the catalytic activity of Pt–MoOx/GN (S) is comparable to that of commercial 30% PtRu/C–JM toward the oxygen reduction reaction via a 4–electron transfer process. In particular, Pt–MoOx/GN (S) displays a more positive reduction potential and stronger stability, which is ascribed to the synergies between MoOx and Pt. Owing to the introduction of photo–responsive MoOx species, Pt–MoOx/GN (S) also exhibits significantly higher mass activity under simulated sunlight illumination, which is 1.62 times as much as that without illumination. The result is in favor of converting solar energy into electric energy during a traditional electrocatalytic process.

Oxidative dehydrogenation of ethane to ethylene is an important process in light olefin industry; however, the over-oxidation of ethane leads to low ethylene selectivity. Here, we report a novel approach to electrochemical oxidative dehydrogenation of ethane in anode in conjunction with CO2 reduction at cathode in a solid oxide electrolyser using a porous single-crystalline CeO2 electrode at 600 °C. We identify and engineer the flux and chemical states of active oxygen species that evolve from the lattice at anode surface to activate and dehydrogenate ethane to ethylene via the reaction of epoxy species. Active oxygen species (O2- , O22- and O2- ) at the anode surface effectively dehydrogenate ethane to ethylene, but O- species tend to induce deep oxidation. We demonstrate exceptionally high ethylene selectivity of 95 % and an ethane conversion of 10 % with a durable operation of 300 h.

Ammonia is a natural pollutant in wastewater and removal technique such as ammonia electro‐oxidation is of paramount importance. The development of highly efficient and low‐costing electrocatalysts for the ammonia oxidation reaction (AOR) and hydrogen evolution reaction (HER) associated with ammonia removal is subsequently crucial. In this study, for the first time, the authors demonstrate that a perovskite oxide LaNi0.5Cu0.5O3‐δ after being annealed in Ar (LNCO55‐Ar), is an excellent non‐noble bifunctional catalyst towards both AOR and HER, making it suitable as a symmetric ammonia electrolyser (SAE) in alkaline medium. In contrast, the LNCO55 sample fired in air (LNCO55‐Air) is inactive towards AOR and shows very poor HER activity. Through combined experimental results and theoretical calculations, it is found that the superior AOR and HER activities are attributed to the increased active sites, the introduction of oxygen vacancies, the synergistic effect of B‐site cations and the different active sites in LNCO55‐Ar. At 1.23 V, the assembled SAE demonstrates ≈100% removal efficiency in 2210 ppm ammonia solution and >70% in real landfill leachate. This work opens the door for developments towards bifunctional catalysts, and also takes a profound step towards the development of low‐costing and simple device configuration for ammonia electrolysers., A non‐noble perovskite electrocatalyst, efficiently catalyzing both AOR and HER under alkaline conditions, is identified. The assembled symmetric ammonia electrolyzer based on this bifunctional catalyst delivers the ammonia removal efficiency of ≈100% in ammonia solution and over 70% in a real landfill leachate, demonstrating the huge potential for development of low‐cost and simple configuration for ammonia electrolyzer.

The Pt-Bi (Bi2O3)/GNs (PVP) composite was synthesized using aqueous solution synthesis and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Raman spectroscopy. It was found that the water-soluble polyvinyl pyrrolidone (PVP) helped to tune the particles’ morphology, resulting in a uniform distribution of Pt-Bi nanoclusters on the surface of graphene. Cyclic voltammetry, chronoamperometry and linear scanning voltammetry (LSV) were used to study the electrocatalytic properties towards a methanol oxidation reaction (MOR) and an oxygen reduction reaction (ORR). The results show that Pt-Bi (Bi2O3)/GNs (PVP) exhibits superior bifunctional electrocatalytic properties for both MOR and ORR, mainly due to the introduction of oxophilic Bi species and the better dispersion of the Pt-Bi nanoclusters. In particular, the electro-photo catalysis for both MOR and ORR occurred under simulated sunlight irradiation due to the existence of photo-responsive Bi species, which is helpful for converting solar energy into electric energy during a traditional electrocatalytic process.