Abstract Microporous and crystalline nickel phosphate nanorods with VSB-5 (Versailles-Santa Barbara-5) structure were uniformly grown around the skeleton of nickel foam under hydrothermal condition in the presence of lithium dihydrogen phosphate. The VSB-5 nanorods exhibited open-framework structure, nanoporosity with a pore diameter of about 1 nm, and typical molecular sieves with zeolitic properties, making them a promising catalyst material for urea oxidation reaction (UOR). A catalyst layer of reticulated VSB-5 nanorods grown on the nickel foam could provide abundant micro-, meso-, and macro-scale pores for hosting electrolyte and expediting the movement of electron, electrolyte, and gaseous products. Electrochemically active surface area (EASA) of the VSB-5 electrode with unique pore structure was considerably greater than that of the nickel hydroxide electrode with granular particles and dense interior. Large EASA and high valence state of nickel species accounted for the superior electrocatalytic performance of the VSB-5 electrode towards UOR compared with the nickel hydroxide electrode. The VSB-5 electrode exhibited higher current density (160 mA cm−2) at 0.6 V vs. SCE (saturated calomel electrode) and lower onset potential (0.27 V vs. SCE) than the nickel hydroxide electrode (75 mA cm−2 and 0.28 V) obtained from the cyclic voltammograms.

中文翻译：

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具有开放框架结构（VSB-5）的沸石磷酸镍纳米棒在尿素电氧化中的催化应用

摘要 在磷酸二​​氢锂存在下，在水热条件下，在泡沫镍骨架周围均匀生长了具有 VSB-5 (Versailles-Santa Barbara-5) 结构的微孔结晶磷酸镍纳米棒。VSB-5纳米棒具有开放的骨架结构、孔径约为1 nm的纳米孔隙率以及具有沸石性质的典型分子筛，使其成为尿素氧化反应（UOR）的有前途的催化剂材料。在泡沫镍上生长的网状 VSB-5 纳米棒催化剂层可以提供丰富的微观、中观和宏观尺度的孔隙，用于容纳电解质并加速电子、电解质和气体产物的运动。具有独特孔结构的 VSB-5 电极的电化学活性表面积 (EASA) 远大于具有颗粒状颗粒和内部致密的氢氧化镍电极。与氢氧化镍电极相比，较大的 EASA 和高价态的镍物种解释了 VSB-5 电极对 UOR 的优异电催化性能。VSB-5 电极在 0.6 V 与 SCE（饱和甘汞电极）下表现出更高的电流密度（160 mA cm-2）和比氢氧化镍电极（75 mA cm-2 和0.28 V) 从循环伏安图中获得。与氢氧化镍电极相比，较大的 EASA 和高价态的镍物种解释了 VSB-5 电极对 UOR 的优异电催化性能。VSB-5 电极在 0.6 V 与 SCE（饱和甘汞电极）下表现出更高的电流密度（160 mA cm-2）和比氢氧化镍电极（75 mA cm-2 和0.28 V) 从循环伏安图中获得。与氢氧化镍电极相比，较大的 EASA 和高价态的镍物种解释了 VSB-5 电极对 UOR 的优异电催化性能。VSB-5 电极在 0.6 V 与 SCE（饱和甘汞电极）下表现出更高的电流密度（160 mA cm-2）和比氢氧化镍电极（75 mA cm-2 和0.28 V) 从循环伏安图中获得。