Processing of organochlorine waste components on bulk metal catalysts

Abstract

A method for destroying chloroorganic waste components on catalysts, particularly bulk metal nickel (99.99%), nichrome (80% Ni and 20% Cr), and chromel (90% Ni and 10% Cr) is proposed. The process is accompanied by the formation of carbon nanofibers (CNFs) with feathery morphology. Catalytic destruction of 1,2-dichloroethane on bulk nickel catalysts is characterized by a long induction period (∼3 h) with spontaneous activation of the alloy’s surface. Preactivation of the catalyst with acids or by alternative treatment in oxidizing and reducing environments shortens the induction period by one order of magnitude. The state of the surface before and after activation is studied by SEM, TEM, and EDX. The activity of catalysts is determined for the decomposition of 1,2-dichloroethane at temperatures of 500 to 700°C. Nichrome exhibited the greatest activity (yield of CNFs, 400 g/g of catalyst); the yield of CNFs on catalysts prepared by coprecipitation and mechanical activation was considerably lower. The proposed approach combines organochlorine waste disposal with the production of a useful product (CNFs). The use of bulk metal catalysts is promising since it simplifies the technology for their preparation, and the absence of carriers makes it easy to cleanse CNFs of impurities of catalyst fragments.