Greatly enhanced reactivity of CaC2 with perchloro- hydrocarbons in a stirring ball mill for the manufacture of alkynyl carbon materials

Calcium carbide (CaC2) is a potential feedstock for various alkynyl chemicals, but its actual activity is very low due to its high lattice energy and insolubility. A stirring ball mill was used here to intensify its reaction with perchloro-hydrocarbons (PCHCs), namely hexachlorobenzene (HCB), hexachloroethane (HCE), tetrachloroethene (TCE) and tetrachloromethane (TCM), forming corresponding alkynyl carbon materials (ACMs), viz. ACM(HCB), ACM(HCE), ACM(TCE) and ACM(TCM), respectively. The reaction intensification may be ascribed to the activation of CaC2 and its effective collision with PCHCs by the intensive impingement of the milling balls. The as-prepared ACMs were characterized by XRD, Raman, elemental analysis, XPS, SEM and BET analysis, and their adsorption performance was evaluated. These ACMs are mesoporous materials with over 70% carbon content, varying amount of acetylenic groups, rich micro-pores and high specific areas ranging from 270 to 970 m(2) g(-1). ACM(HCB) is found to be a promising sorbent with adsorption capacity of 514.7 mg-Hg g(-1) for HgCl2 aqueous solution and 24.4 mg-S g(-1) for DBT oil, which is much superior to most of carbonaceous sorbents due to its rich micro-porosity and abundant acetylenic groups.