Cobalt Sulfide Is Used To Catalyze The Study Of The Reduction Reaction Of P-nitrophenol

As an indispensable industrial intermediate,aniline compounds are widely used in the synthesis of pharmaceuticals,dyes,photo developers,et al.At present,the most effective method for preparing aniline compounds is to reduce nitrobenzene compound under the action of catalyst.Among them,the most representative one is the catalytic hydrogenation reduction of 4-nitrophenol to obtain 4-aminophenol.This reaction not only has important practical application value,but also can be used to test the hydrogenation catalytic performance of the catalyst.In order to deal with the high cost and scarcity of precious metal catalysts,this paper mainly tests the applicability of cobalt sulfide for the reduction of 4-nitrophenol and initially explores the catalytic mechanism.And we design the supported catalyst to avoid agglomeration of catalyst particles and further reducing production costs.The work content is as follows:First,three cobalt sulfide catalysts,Co9S8,CoS and CoS2,were prepared and their applications in the catalytic reduction of 4-nitrophenol to 4-aminophenol were studied.Co9S8 has the fastest surface electron transport efficiency and the highest H2 adsorption capacity,making it the best catalyst among the three.CoS has higher electron transfer efficiency and stronger H absorption capacity than CoS2.Therefore,the catalytic activities of the three catalysts showed the following trends under the same reaction conditions:Co9S8>CoS>COS2.Finally,based on a series of characterizations such as XPS,H2-TPD,EIS,etc.,a reasonable catalytic mechanism is proposed to help understand the catalytic effect of CoxSy.Second,a resin-derived carbon-supported metal/metal sulfide catalyst is obtained by using the sulfonic acid type ion exchange resin as a sulfur source,four different catalysts are obtained from different reaction temperatures and solvent types:Co-Co9S8/C,,Co9S8/C-w25,Co9S8/C-w80 and Co/C.The catalytic activity of the four catalysts decreases in turn.The morphology of the TEM shows that the Co-Co9S8 particles in the Co-Co9S8/C catalyst are highly dispersed on the primary carbon.The results of IIRTEM and XPS indicate that there is an interaction between Co and oxygen to promote the catalytic reaction together.