Bimetallic Fe-Ni/SiO2 catalysts for furfural hydrogenation: Identification of the interplay between Fe and Ni during deposition-precipitation and thermal treatments
作者:Dichao Shi、Qifeng Yang、Christi Peterson、Anne-Félicie Lamic-Humblot、Jean-Sébastien Girardon、Anne Griboval-Constant、Lorenzo Stievano、Moulay T. Sougrati、Valérie Briois、Paul A.J. Bagot、Robert Wojcieszak、Sébastien Paul、Eric Marceau
DOI:10.1016/j.cattod.2018.11.041
日期:2019.8
initially leads to the formation of an ill-crystallized Fe-containing Ni(II) 1:1 phyllosilicate, which reduces under hydrogen at 700 °C into bimetallic fcc Fe-Ni nanoparticles of 5.4 nm in average. Compared with the composition of the DPU solution (50 Fe at %, 50 Ni at %), an excess of Ni is detected on the catalyst (38 Fe at %, 62 Ni at %), due to the preferential reaction of Ni2+ ions with silica. In
已经报道了负载的Fe-Ni催化剂在不饱和有机分子的氢化中的活性和选择性。然而,当通过浸渍制备氧化物负载的催化剂时,双金属纳米颗粒的尺寸和组成的控制仍然是瓶颈,并且应当研究替代方法。以Ni(II)和Fe(II)硫酸盐作为前体盐开始,在惰性气氛中在SiO 2上用尿素(DPU)进行沉积沉淀,最初会导致形成结晶不良的含Fe的Ni(II)1: 1种页硅酸盐,在700°C的氢气下可还原成双金属fccFe-Ni纳米粒子平均为5.4 nm。与DPU溶液的成分(50 Fe%,50 Ni%)相比,由于Ni 2+的优先反应,在催化剂上检测到过量的Ni(38 Fe%,62 Ni%)。离子与二氧化硅。原位X射线吸收光谱和57 FeMössbauer光谱表明,在高于350°C的条件下,Ni还原中心的形成触发了Fe离子向金属态的还原,此后逐渐进行,导致过量的铁在双金属颗粒的外壳中。单个Fe-Ni颗粒的组成表明标准偏差为8%。双金属Fe-Ni