小龙虾壳制备固体碱及其Knoevenagel缩合反应性能

Facile Synthesis of Solid Bases from Crayfish Shell for Knoevenagel Condensations

以小龙虾壳为原料,通过高温煅烧的方法,制备出氧化钙型固体碱催化剂,该方法简便易行,原料便宜易得。运用X射线衍射(XRD)、红外光谱(FT-IR)和氮气吸脱附技术(N_(2)-sorption)对催化剂的结构形貌和化学组成进行了表征,以二氧化碳程序升温脱附(CO_(2)-TPD)和酸碱滴定方法确定催化剂的碱强度分布和碱量。当煅烧温度为750℃时,固体碱表现出最优化的碱量和碱强度分布性质,该催化剂可高效催化多种醛类底物的Knoevenagel缩合反应,且通过煅烧的方法可有效实现催化剂的活化再生。本研究对高值化利用废弃生物质具有积极的探索意义。

The CaO typed solid base with high catalytic efficiency was synthesized by high temperature calculation of crayfish shell.The preparing produce was facile,and the crude materials were cheap and readily available.The morphology,structure and the chemical compositions of solid bases were analyzed with X-ray diffraction(XRD),Fourier transform infrared spectra(FT-IR)and nitrogen sorption technologies(N_(2) sorption).The total basic amount and distribution of active sites with different basic strength were determined with acid-base titration and CO_(2)-TPD technologies.The solid base synthesized at 750℃showed the highest amount of basic sites and the optimized distribution of basic strength.The optimized solid base exhibited excellent catalytic performance in Knoevenagel condensation for various aldehydes,and the catalysts could be regenerated with calculations.This research will be of significance for high-valued utilization of biomass wastes.