查找使用阿拉丁产品的科研文献

Direct synthesis of H2O2 over Pd–M@HCS (M = Sn, Fe, Co, or Ni): effects of non-noble metal M on the electronic state and particle size of Pd

Quansheng Wu,Songhua Zhou,Chengbing Fu,Jiesong Zhang,Bo Chen,Hongyan Pan,Qian Lin

For the mono-metal Pd based catalysts, the O–O bond in O2 and H2O2 is easily dissociated due to the higher energy sites of Pd, which decreases the selectivity and productivity of H2O2. To address this issue, non-noble metals M (M = Sn, Fe, Co, Ni) were doped into palladium precursors to create a series of yolk–shell structure bimetallic catalysts Pd–M@HCS (H = hollow; C = carbon; S = sphere) with Pd–M as the core and porous carbon as the shell. The results indicated that the catalyst Pd–M@HCS doped with Sn, Fe, Co, and Ni has a weak dissociation ability for O2, and both the adsorption and dissociation ability for H2 are improved. Of these catalysts, the catalyst Pd–Sn@HCS gives the best performance, which is benefited by the suitable Pd–Sn nanoparticle size and the best Pd2+/Pd0 ratio. The influence of the nPd/nSn ratio in the Pd–Sn@HCS system on catalyst performance was further explored, and the findings revealed that Pd–Sn@HCS had the best catalytic activity and stability when the nPd/nSn ratio was 2. The catalyst's H2 conversion, H2O2 selectivity, and productivity were 35%, 97%, and 3961 mmol gPd−1 h−1, respectively. After 10 cycles, the H2O2 productivity of this catalyst remained at 92.1%, which was greater than the H2O2 productivity of the typical Pd-based catalyst Pd/C, which stayed at 37% under the same conditions.