Synthesis Of Nitrogen Doped Carbons And Their Catalytic Performance In Acetylene Hydrochlorination

With the increase in demand of environmental protection,it has become the bottle-neck problem for the industry of PVC to develop efficient mercury-free catalysts for acetylene hydrochlorination.Metal-free carbon based catalyst is one promising choice due to its unique advantages of low production cost,good corrosion resistance,favorable thermostability,et al.In this paper,the methods were studied to post-modify commercial activated carbon and direct synthesize wheat starch-derived mesoporous starbon.The influence of carbons materials' properties such as surface functional groups,ash,graphitic degree,nitrogen doping on catalytic performance in acetylene hydrochlorination were also investigated.Major conclusions in this article are listed below:1.With the increase of carboxyl group and ash,catalytic performance decreases.Under similar condition of specific surface area,ash content and pore structure,the initial activity of various carbon sources decreases in the orders as follow: AC-Coal > AC-Wood > AC-Coconut.The results may be related to the different graphitic degree of various carbon sources.2.Nitrogen can be doped successfully in activated carbon by post-modified method using urea and the catalytic performance is improved linearly with the increase of nitrogen content.3.Protein-rich wheat starch(1.9 wt% of nitrogen)was used as carbon resource to synthesize granular mesoporous starbon through dry grinding method using nano-silica as a hard template.Compared to mesoporous carbon derived from sugar and activated carbon,the starbon displays considerable catalytic performance for the acetylene hydrochlorination due to the high nitrogen content(1.6 %).Melamine was added to starch to adjust the nitrogen content of starbon while grinding.The conversion of acetylene on this starbon increases with the increase of nitrogen content when it is lower than 4 %.However,the conversion of acetylene cannot be improved further when the nitrogen content is higher than 4 %.