Lekgetho Tumisang, Tukulula Matshawandile, Mabena Letlhogonolo Fortunate, Maphoru Mabuatsela Virginia
Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X01, Durban, 4000, South Africa.
ChemistryOpen. 2025 Jun;14(6):e202400484. doi: 10.1002/open.202400484. Epub 2025 Apr 10.
Herein, silica-supported Au-Ru catalysts with 5% loading for each metal were prepared by microwave-assisted loading (MW) and deposition (DP) methods. Au-Ru nanoparticles are obtained on MW-5Au5Ru while short Au-Ru nanochains are obtained on DP-5Au5Ru. The performance of the catalysts is tested through the oxidation of 2,3,5-trimethylhydroquinone (TMHQ) and 4-methoxy-1-naphthol (MNL) with HO, in which 2,3,5-trimethyl-1,4-benzoquinone (TMBQ) and 4,4'-dimethoxy-2,2'-binaphthalenylidene-1,1'-dione (BNP) are produced as main products, respectively. Catalytic data obtained for the oxidation of TMHQ demonstrate that the structures of the catalysts, type of solvent, and reaction temperatures used have a significant influence on the activities and selectivities of the catalysts. When MeOH and MeNO are used at room temperature (RT) in the oxidation of TMHQ on MW-5Au5Ru catalyst, 58.2% and 100% conversions of TMHQ are achieved, respectively. Both MW and DP-synthesized catalysts are highly active in the oxidation of TMHQ. Similar to TMHQ, the catalytic outcomes on the oxidative coupling of MNL highly depend on the temperature and structure of the catalyst. For example, 34% and 96% conversions of MNL are achieved at RT and 60 °C, respectively, over MW-5Au5Ru catalyst in MeOH. However, MNL conversion of 82% is achieved on DP-5Au5Ru catalyst in MeOH at RT.
在此，通过微波辅助负载（MW）和沉积（DP）方法制备了每种金属负载量为5%的二氧化硅负载的金-钌催化剂。在MW-5Au5Ru上获得金-钌纳米颗粒，而在DP-5Au5Ru上获得短的金-钌纳米链。通过用HO氧化2,3,5-三甲基对苯二酚（TMHQ）和4-甲氧基-1-萘酚（MNL）来测试催化剂的性能，其中分别以2,3,5-三甲基-1,4-苯醌（TMBQ）和4,4'-二甲氧基-2,2'-联萘叉-1,1'-二酮（BNP）作为主要产物。TMHQ氧化得到的催化数据表明，催化剂的结构、所用溶剂的类型和反应温度对催化剂的活性和选择性有显著影响。当在室温（RT）下在MW-5Au5Ru催化剂上氧化TMHQ时使用甲醇和甲腈，TMHQ的转化率分别达到58.2%和100%。MW和DP合成的催化剂在TMHQ氧化中均具有高活性。与TMHQ类似，MNL氧化偶联的催化结果高度依赖于催化剂的温度和结构。例如，在甲醇中，在MW-5Au5Ru催化剂上，室温（RT）和60°C时MNL的转化率分别达到34%和96%。然而，在室温（RT）下在甲醇中，DP-5Au5Ru催化剂上MNL的转化率达到82%。
