Anthraquinone hydrogenation to produce H_(2)O_(2) is an economically interesting reaction with great industrial importance.Here,we report a series of Pd/xAl catalysts with different AlCl_(3) contents by a conventional...Anthraquinone hydrogenation to produce H_(2)O_(2) is an economically interesting reaction with great industrial importance.Here,we report a series of Pd/xAl catalysts with different AlCl_(3) contents by a conventional stepwise impregnation method.The optimal Pd/1.0Al catalyst exhibits a higher performance toward anthraquinone hydrogenation with 8.3 g·L^(-1)hydrogenation efficiency,99.5%selectivity and good stability,obviously superior to that of Pd/Al_(2)O_(3) catalyst(5.2 g·L^(-1)and 97.2%).Detailed characterization demonstrates that AlCl_(3) can be grafted on the γ-Al_(2)O_(3) support to obtain a modified support with abundant surface weak acid and Lewis acid,which can adsorb and activate anthraquinone.Meanwhile,its steric hindrance could isolate and disperse active metals to form more active sites.The synergies between metal sites and acid sites promotes the anthraquinone hydrogenation.Furthermore,the good stability after grafting AlCl_(3) could attribute to the enhanced metal-support interaction inhibiting metal particles agglomeration and leaching.展开更多
A novel coupling reaction of diaryl methanols with ketones or aldehydes has been developed under the catalysis of AlCl_(3).Various ketones and aldehydes could couple with 9H-xanthen-9-ol smoothly,affording coupling pr...A novel coupling reaction of diaryl methanols with ketones or aldehydes has been developed under the catalysis of AlCl_(3).Various ketones and aldehydes could couple with 9H-xanthen-9-ol smoothly,affording coupling products in 48%-88%yields.A plausible mechanism using AlCl_(3) to activate both diaryl methanol and ketone or aldehyde is proposed.展开更多
基金the National Natural Science Foundation of China(21776215 and 21621004).
文摘Anthraquinone hydrogenation to produce H_(2)O_(2) is an economically interesting reaction with great industrial importance.Here,we report a series of Pd/xAl catalysts with different AlCl_(3) contents by a conventional stepwise impregnation method.The optimal Pd/1.0Al catalyst exhibits a higher performance toward anthraquinone hydrogenation with 8.3 g·L^(-1)hydrogenation efficiency,99.5%selectivity and good stability,obviously superior to that of Pd/Al_(2)O_(3) catalyst(5.2 g·L^(-1)and 97.2%).Detailed characterization demonstrates that AlCl_(3) can be grafted on the γ-Al_(2)O_(3) support to obtain a modified support with abundant surface weak acid and Lewis acid,which can adsorb and activate anthraquinone.Meanwhile,its steric hindrance could isolate and disperse active metals to form more active sites.The synergies between metal sites and acid sites promotes the anthraquinone hydrogenation.Furthermore,the good stability after grafting AlCl_(3) could attribute to the enhanced metal-support interaction inhibiting metal particles agglomeration and leaching.
基金Financial supports from MOST of China(973 program 2011 CB808600)National Natural Science Foundation of China(Nos.21072091 and 21372195)are gratefully acknowledged.
文摘A novel coupling reaction of diaryl methanols with ketones or aldehydes has been developed under the catalysis of AlCl_(3).Various ketones and aldehydes could couple with 9H-xanthen-9-ol smoothly,affording coupling products in 48%-88%yields.A plausible mechanism using AlCl_(3) to activate both diaryl methanol and ketone or aldehyde is proposed.
