多元体系下低金含量的乙炔氢氯化无汞金催化剂复配效应

Due to mercury catalyst in acetylene hydrochlorination toxic and pollute seriously. We intend to start the topic of this research on match effect based on multiple system low-gold-content mercury-free acetylene hydrochlorination gold catalyst. Using the impregnation method to prepare the supported(activated carbon, silicon oxide and aluminium oxide etc. as the support) low-gold-content (≤1.0 wt%) binary Au catalytic system (Au-M/support(M=Cu,Sn)) and ternary Au catalytic system (Au-M-I/support (M=Cu,Sn;I=Bi,Zn)) acetylene hydrochlorination catalyst ,and research the scientific rules of match effect of the prepared catalysts. Then the characterization of prepared catalysts with structure analysis and the evaluation of catalytic performance acetylene hydrochlorination and physico-chemical characterizations will be experimentized to further explain the match effect including electronic effect and carrier effect of catalysts. Moreover, we will investigate the formation conditions of the active sites on different supports and supports that match the active sites by analysis method comparison. On the basis of the above discussion, further investigate the influence that different synthesis methods to match effect on catalysts and optimize preparation condition and regulate and control the catalytic performance of mercury-free acetylene hydrochlorination catalysts on binary and ternary system from the point of synthesis methods and technical routes. Finally, investigations on the catalytic reaction mechanism will be carried out. The systematic comparative study on scientific rules of binary system Au-M/C (M=Cu,Sn)and ternary system Au-M-I/C (M=Cu,Zn; I=Bi,Zn) mercury-free acetylene hydrochlorination catalysts,illumination on the relation between match effect and Au content will be proceeded, seeking a scientific guidance to get the correct minimum gold content in the end, thus, a scientific foundation for the research of low cost acetylene hydrochlorination catalysts will be established.

针对乙炔氢氯化反应汞催化剂毒性大污染严重等缺点，本研究以多元体系下低金含量的乙炔氢氯化无汞金催化剂复配效应为题，采用浸渍法制备低金含量（≤1.0wt%）二元金催化剂体系（Au-M/载体(M=Cu,Sn)）和三元体系（Au-M-I/载体(M=Cu,Sn;I=Bi,Zn)）负载型乙炔氢氯化催化剂(载体拟选择活性碳、氧化硅、稀土氧化物等)，研究催化剂的复配规律，对其结构和反应活性等进行评价及物化表征，阐述催化剂的复配效应包括电子效应和载体效应。此外，通过对比分析法探讨在不同载体上形成活性中心的条件以及与之相匹配的载体，进一步探讨制备方法对催化剂复配效应的影响，优化制备条件，调控二元体系和三元体系无汞催化剂性能。最后，开展相应的催化反应机理研究，系统对比分析二元和三元体系的复配规律，阐述其复配效应与最低金含量的关系，从而为正确获取最低金含量寻求科学指导，为研发低成本乙炔氢氯化金催化剂奠定科学基础。

针对乙炔氢氯化反应汞催化剂毒性大污染严重等缺点，本项目以多元体系下低金含量的无汞金催化剂和低钌含量的无汞催化剂为研究对象，采用浸渍技术制备了系列低金含量催化剂和系列低钌含量催化剂，分别通过TG、SEM、TEM 、H2-TPR、BET、XRD、XPS等手段等对所制备的催化剂进行了表征和分析。对低金含量催化剂研究结果发现，采用超声辅助浸渍技术制备了0.25Au0.75Ru/Coconut AC、其在乙炔氢氯化反应中的乙炔转化率高达95.6%，氯乙烯选择性达到99.8%，明显高于目前通常文献报道的金含量为1%的单金（Au1%/Coconut AC）催化剂。通过组分相互作用首次实现了乙炔氢氯化催化剂在保证活性不变的情况下降低金含量的功效。按照Au和Ru之间的协同作用理论，研究将原总负载量为1%的Au0.75Ru0.25/Coconut AC催化剂中的贵金属Au负载量从0.75%降至0.10%，制备出形成的总负载量为0.35%的Au0.1Ru0.25/Coconut AC催化剂，此时该催化剂乙炔的转化率能够达到84%，氯乙烯选择性为99.6%，同时该催化剂要比相同金含量的单金催化剂（Au0.1/Coconut AC）和相同钌含量的单钌催化剂（Ru0.25/Coconut AC）更高，而且也高于工业高汞和低汞催化剂。与此同时，我们还发现通过钌、铜和钽等元素的添加，可以不同程度地降低金含量，改善了低金催化剂的乙炔氢氯化反应性能，同时采用1,3-二甲基-2-咪唑啉酮（DMEU）、氨基磺酸（SN）、六甲基磷酰三胺（HMPA）改性乙炔氢氯化钌基催化剂（钌含量为0.25 wt%）,并同金基催化剂（金含量为0.25 wt%）和未改性的钌基催化剂（钌含量为0.25 wt%）进行了简单催化性能比对，进一步探索了反应机理，最终研究开发出不含金只含少量钌（钌含量为0.25 wt%）但用氨基磺酸改性的无金低成本催化剂（Ru-x% SN/AC）反应8 h后乙炔转化率为88.7%，氯乙烯选择性约为99%。阐述了所制备的催化剂的组成、结构与乙炔氢氯化反应催化性能之间协同匹配关系。由于本项目具有复杂性和实验性强的特点，再加上突发的三年新冠疫情等严重地影响本项目的进度和深度，到目前为止，本项目对特殊的催化剂的制备技术申请了4项专利，已全部公开，投稿国内学术会议论文6篇。本项目已直接培养出毕业硕士研究生3名。