前驱体溶液中Fe2+与Fe3+物质的量比对Au/α-Fe2O3催化剂低温水煤气变换性能的影响

摘要

A series of Au/α-Fe2O3 catalysts for water-gas shift reaction were prepared in precursor solution with different Fe2+/Fe3 ＋ molar ratios and characterized by XRD, Raman spectrum and H2-TPR. The results showed that the catalytic activity of Au/α-Fe203 catalysts for the low-temperature water-gas shift reaction were remarkably influenced by Fe2＋/Fe3＋ molar ratios in the precursor solution. The introduction of Fe2＋ ion induced the changes in crystallinity, concentration of defects and crystal size of catalyst support α-Fe2O3, thereby the dispersion of the nano-gold particles and the interaction between nano-gold particles and α-Fe2O3 were also influenced. The optimum molar ratio of Fe2+/Fe3+ was 1:6 and the corresponding sample AF-1: 6 exhibited superior catalytic activity for low-temperature water-gas shift reaction, with CO conversion of 78.02％ at 150 ℃.%改变前驱体溶液中Fe<'2+>与Fe<'3+>物质的量比制备了系列Au/α-Fe<,2>O<,3>水煤气变换催化剂,并运用XRD、拉曼光谱和H<,2>-TPR对样品进行表征.结果表明,Fe<'2+>与Fe<'3+>物质的量比的变化对Au/α-Fe<,2>O<,3>催化剂低温水煤气变换活性具有显著影响,这是由Fe<'2+>的添加改变了载体α-Fe<,2>O<,3>的结晶度、结晶缺陷及晶粒大小,从而影响金纳米颗粒的分散及与载体间的相互作用.Fe<'2+>与Fe<'3+>适宜物质的量比为1:6,所得样品AF-1:6具有最佳低温活性,150℃,CO转化率达78.02%.