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In this work, two different types of catalysts with MgO support for aqueous phase reforming of glycerol were prepared by the sol-gel method and calcining method, respectively, and the active metals (nickel or/and cobalt) were added by the initial wet impregnation (IWI) method. It is found that the catalyst supported by gelatinous MgO presents better dispersion and the amount of hydrogen produced by the catalyst containing gelatinous MgO support is more than 1.5 times compared with other catalysts. For the Ni–Co bimetallic catalysts, the higher reaction temperature is beneficial to hydrogen yield, but decreases hydrogen selectivity. A high concentration of glycerol increases hydrogen yield and selectivity. Introducing CaO as an absorbent in aqueous phase reforming can improve WGS reaction and reduce methanation reaction through in-situ CO 2 removal and capture. The gelatinous Ni–Co/MgO catalyst presents superior activity and multi-cycle stability. [Display omitted] [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) power generation coupled with proton exchange membrane (PEM) water electrolysis favors improving the solar energy utilization and producing green hydrogen. But few systems proposed focus on achieving all-day stable hydrogen production, which is important for the future large-scale hydrogen utilization. Herein, a PV-Battery-PEM water electrolysis system for hydrogen production was constructed. An energy management strategy (EMS) was proposed to achieve the goal of all-day stable hydrogen production, improve energy utilization efficiency and reduce light discard rate. The PV power generation system, battery system and PEM electrolyzer for hydrogen production system were first established by Matlab/Simulink platform. Then, the overall PV-Battery-PEM electrolyzer system for hydrogen production was constructed, and the effectiveness of EMS was verified. The energy efficiency of the system under different working conditions with and without battery for energy storage was analyzed. The results show that the proposed energy management strategy can meet the purpose of all-day stable hydrogen production. Under the same working conditions, the energy efficiency of the system with battery for energy storage increases by 2–4% compared with the system without battery for energy storage, which indicates that the addition of energy storage can improve the energy utilization and reduce the light discarding. [Display omitted] [ABSTRACT FROM AUTHOR]

Semiconductors often have limited photocatalytic water-splitting performances owing to the narrow light absorption and low effective carrier density. In response to these challenges, we report the discovery of metallic amorphous cobalt boride (Co 2 B) as the first first-row transition metallic photocatalyst. It was prepared via a simple chemical reduction method and performs efficient water splitting spanning the UV, visible light and near-infrared region (NIR) via interband transitions. It achieves bifunctional water splitting activities with H 2 evolution rate of 202.3 μmol h−1 g−1 and O 2 evolution rate of 74.8 μmol h−1 g−1, superior to the existing (semi-)metallic photocatalysts. The material shows over 1 % apparent quantum efficiency (AQE) and 20 % incident photon to current conversion efficiencies (IPCE) at the NIR region >800 nm. Theoretical and photophysical experimental studies synergistically confirm that the metallic nature with high carrier concentrations and amorphous structure with abundant active sites contribute to the good water splitting performance of Co 2 B. This research sets the foundation for the utilization of highly efficient transition metal-based metallic photocatalysts in photocatalysis across the entire solar spectrum. [Display omitted] [ABSTRACT FROM AUTHOR]

Semiconductors often have limited photocatalytic water-splitting performances owing to the narrow light absorption and low effective carrier density. In response to these challenges, we report the discovery of metallic amorphous cobalt boride (Co 2 B) as the first first-row transition metallic photocatalyst. It was prepared via a simple chemical reduction method and performs efficient water splitting spanning the UV, visible light and near-infrared region (NIR) via interband transitions. It achieves bifunctional water splitting activities with H 2 evolution rate of 202.3 μmol h−1 g−1 and O 2 evolution rate of 74.8 μmol h−1 g−1, superior to the existing (semi-)metallic photocatalysts. The material shows over 1 % apparent quantum efficiency (AQE) and 20 % incident photon to current conversion efficiencies (IPCE) at the NIR region >800 nm. Theoretical and photophysical experimental studies synergistically confirm that the metallic nature with high carrier concentrations and amorphous structure with abundant active sites contribute to the good water splitting performance of Co 2 B. This research sets the foundation for the utilization of highly efficient transition metal-based metallic photocatalysts in photocatalysis across the entire solar spectrum. [Display omitted] [ABSTRACT FROM AUTHOR]