Hao Tian,Xinyu Li,Sai Chen,Liang Zeng,Jinlong Gong
Reducible oxides ( e.g ., CeO 2 and ZrO 2 ) supported 3d transition metals ( e.g ., Ni, Co, Pt) exhibit remarkable catalytic activity in reactions that involve water activation, such as steam reforming and water gas shift. This paper describes the influence of Sn addition on the performance of Ni/CeO 2 catalysts in ethanol steam reforming. 0.25 wt% Sn addition improved the stability of Ni/CeO 2 by forming Ni-Sn bimetallic nanoparticles with Sn enriched surfaces to suppress the carbon deposition. Ni 0. 25 Sn/CeO 2 kept over 90% ethanol conversion in a 20 h stability test at 600 °C with over 60% hydrogen selectivity under a gas hourly space velocity of 57000 mL/(g•h). However, the presence of Sn decreased the overall oxygen storage capacity and oxygen mobility of NiSn/CeO 2 , which hampered water activation process and coke elimination occurring at the interface between Ni and CeO 2 . Additionally, ethanol decomposition was also suppressed due to the coverage of Sn atoms on Ni surfaces.
Durability is one prerequisite for material application. Photoelectrochemical decomposition of seawater is a promising approach to produce clean hydrogen by using solar energy, but it always faces the problem of serious Cl − corrosion. We find that the main deactivation mechanism of the photoanode is oxide surface reconstruction accompanied by the coordination of Cl − during seawater splitting, and the stability of the photoanode can be effectively improved by enhancing the metal-oxygen interaction. Taking the metastable β -Fe 2 O 3 photoanode as an example, Sn added to the lattice can enhance the M–O bonding energy and hinder the transfer of protons to lattice oxygen, thereby inhibiting excessive surface hydration and Cl − coordination. Therefore, the bare Sn/ β -Fe 2 O 3 photoanode delivers a record durability for photoelectrochemical seawater splitting over 3000 h.
危险品化学品经营许可证（带存储）