Preparation,Sulfonation And Catalytic Properties Of Coconut Shell Activated Carbon

There expounded a new kind coconut shell activated carbon that was prepared by impregnation and carbonization,and used the coconut shell activated carbon as carbon source and sulfuric acid as sulfonated agent,a sulfonated sulfonated coconut shell carbon based solid acid(SCSAC)with porous characteristics was prepared by one pot sulfonated method.The intermediate products and the coconut shell carbon based solid acids in the preparation process were characterized by FT-IR,SEM,XRD and so on.Taking SCSAC as catalyst,esterification reaction of acetic acid and n-butanol as probe experiment,we explored the catalytic mechanism of SCSAC catalyst and optimized its synthesis conditions to improve its catalytic performance.In addition,to expand the application of SCSAC,explore its catalytic performance in other reactions,investigated the esterification of other acids and esters in the same conditions,as well as alcohols,diols and ketone condensation reaction.The catalytic properties of two kinds of common solid acid catalysts,SCSAC,sulfonated activated carbon and strong acid cation exchange resin,were compared,and the effects of different carbon sources and different group supports on the performance of the catalysts were compared.Finally,the esterification reaction of acetic acid and n-butanol is used as a probe.The reutilization of the solid acid catalyst is discussed through repeated use of SCSAC catalyst.The following conclusions are drawn:(1)The synthesis of intermediate products and catalyst SCSAC were characterized and analyzed by FT-IR,TGA,SEM and so on.After carbonization,the peak of cellulose peaks disappeared and the absorption peaks of the amorphous carbon structure appeared.It showed that the carbonization process formed a large number of amorphous carbon structures in XRD.The characteristic peak of-SO3H was found at 1178cm-1?1034 cm-1 and 589-1cm,it's seemed that the sulfonic group was successfully introduced in FT-IR.Nitrogen adsorption desorption test showed that the specific surface area and pore volume of the material increased with the increase of carbonization temperature,and the nanoparticle channel increased,and the mesoporous pore decreased.In TUV,the content of C elements in the samples after carbonization is greatly improved and after sulfonated samples,the content of S elements increased from 0%to 2.927%.In SEM,SCSAC has porous and porous honeycomb structure with high specific surface area and developed pass,and the pore size is 0.5-1.5 m.(2)The five combination conditions of coconut coconut carbon were optimized with the esterification of acetic acid and n-butanol as a probe:the dosage ratio of raw material and activator,carbonization temperature,carbonization time,sulfonator dosage ratio and sulfonation time.The results show that,it has the highest catalytic efficiency when the raw material and activator dosage ratio is 1:1,the holding time is 2h and the sulfonating agent sample dosage ratio is 1g:20mL.The carbonization temperature of 350 ? has the highest catalytic efficiency,but the catalyst carbonization effect is poor,low yield,the 450? for the optimal carbonization temperature and the sulfonation time has little effect on the catalyst,2h as the optimal reaction time.(3)The application of SCSAC in esterification and ketal reaction was investigated.The results showed that:in the esterification reaction,the esterification conversion rate of low carbon chain acid is above 97%,the conversion rate of monohydric alcohols and diolsreached with cyclohexanone are 76.7%and 95%.(4)The esterification of acetic acid and n-butanol was used as a probe to compare the performance of three solid acid catalysts:SCSAC,sulfonated activated carbon and strong acid cation exchange resin.The results showed that the acid catalytic performance of SCSAC was much higher than that of the other two kinds of solid acids.(5)Repeated use of SCSAC catalysts seven times to investigate the reproducibility of the catalyst showed that:the conversion rate of catalytic reaction reached 87.9%after 7 times in the system of 80 C,and the conversion rate of catalytic reaction reached 71.9%after 7 times in 120 C system.