Na Tong,Ying Wang,Yang Liu,Minbo Li,Zizhong Zhang,Huijuan Huang,Tao Sun,Jinxiang Yang,Fuying Li,Xuxu Wang
Photocatalytic ammonia synthesis is of great importance but remains very challenging in photocatalysis. Here, we fabricated a photocatalytic reaction system for the efficiently photocatalytic nitrate reduction to ammonia under UV irradiation using PdSn/NiO/NaTaO 3 :La as a photocatalyst in the presence of formic acid. Several important factors of the photocatalytic performance were investigated, including initial concentration of the nitrate solution, initial pH value and cocatalyst loadings. Nitrate conversion reaches 100% and ammonia selectivity is 72% over the optimum photocatalyst with 5% bimetallic PdSn alloy and 0.2% NiO loadings. The outstanding performance of photocatalyst can be ascribed to both the strong adsorption of nitrite on NiO and the efficient separation of electron-hole pairs by PdSn bimetallic alloy. Besides as the hole scavenger, formic acid also provides not only carboxyl anion radicals for nitrate reduction but also the in-situ buffer effect on ammonia formation. These results give inspiration for designing the reactive system with efficient photocatalytic ammonia synthesis.
Developing a novel catalyst with lower noble-metal loading and higher catalytic efficiency is significant for promoting the widespread application of direct alcohol fuel cells (DAFCs). In this work, poly(3,4-ethylenedioxythiophene) (PEDOT) supported the PdSn alloy (PdSn/PEDOT) were simply synthesized and their electrocatalytic performance toward the oxidation of ethylene glycol and ethanol (EGOR and EOR) were investigated in alkaline media, respectively. In comparison with other control catalysts, the optimized Pd 4 Sn 6 /PEDOT catalyst exhibits the highest mass activity (7125/4166 mA mg Pd −1 ) and specific activity (26/15 mA cm −2 ) towards EGOR/EOR. The mass activity of Pd 4 Sn 6 /PEDOT for EGOR and EOR are 11.9 and 10.9 times higher than commercial Pd/C, respectively. Moreover, chronoamperometry (CA) and successive cyclic voltammetry (CV) tests show that the CO resistance ability and durability of the Pd 4 Sn 6 /PEDOT catalyst were superior to Pd 4 Sn 6 , Pd/PEDOT and commercial Pd/C catalysts, which can be attributed to the d-band center of Pd can be effectively downshifted and the interface strain effect between electrons caused by the conjugated structure between PEDOT groups. This work provides an effective strategy for the development of highly efficient anode catalysts of DAFCs.
Nannan Zhang,Jie Li,Wanyu Liang,Yangping Zhang,Zhengying Wu,Yukou Du
2D nanodendrites (NDs) and nanosheets (NSs) have been regarded as efficient nanocatalysts for enhancing the electrocatalytic performance due to their low coordinated sites and abundant electrocatalytic centers. Nevertheless, it remains challenging to construct advanced NDs and NSs in a single reaction system. Herein, by tuning the volume ratios of mixed solvents, the reduction and diffusion rate of Sn2+ on Pd NSs template was rationally controlled to prepare PdSn NDs and PdSn NSs. Ascribed to the open 2D nanostructure, high specific surface area, and robust synergistic effect, the as-prepared PdSn NDs and PdSn NSs exhibited distinguished electrocatalytic activities for ethylene glycol oxidation reaction (EGOR) and ethanol oxidation reaction (EOR), as well as commendable electrocatalytic durability, which were far superior to the Pd NSs and commercial Pd/C. In addition, the PdSn NDs exhibited enhanced reaction kinetics because the characteristic branch structure exposed a high density of active sites. This work may provide significant guidance for preparing excellent nanocatalysts with various morphological features by simply optimizing the content of the coexisting solvents.
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