响应面法优化废旧毛涤粘面料溶解工艺

采用磷酸/多聚磷酸混酸溶剂体系对废旧毛涤粘混纺面料中的粘胶进行溶解,混酸溶剂体系溶解粘胶的最佳工艺为P_2O_5质量分数74%,固含质量分数14%,温度25℃。采用由尿素、亚硫酸氢钠和十二烷基硫酸钠(SDS)组成的还原C体系对混纺面料中的羊毛纤维进行溶解,通过响应面法探讨了尿素浓度、亚硫酸氢钠浓度、SDS浓度、时间等参数对羊毛溶解率和角蛋白提取率的影响,优化羊毛溶解工艺条件为:尿素400 g/L,亚硫酸氢钠40 g/L,SDS 20 g/L,时间6 h,浴比1∶20,p H为11;最优溶解方案下的羊毛溶解率和角蛋白的提取率分别是89.53%和49.32%。

Architecture of PtFe/C catalyst with high activity and durability for oxygen reduction reaction

A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characterization reveal that PtgFe alloy formation occurs during high-temperature reduction and that unstable Fe species are dissolved into acid solution. The difference in Fe concentration from the core region to the surface and strong O-Fe bonding may drive the outward diffusion of Fe to the highly corrugated Pt-skeleton, and the resulting highly dispersed surface FeOx is stable in acidic medium, leading to the construction of a PtBFe@Pt-FeOx architecture. The as prepared PtFe/C catalyst demonstrates a higher activity and comparable durability for the oxygen reduction reaction compared with a Pt/C catalyst, which might be due to the synergetic effect of surface and subsurface Fe species in the PtFe/C catalyst.