Vitamin B12-mediated hydrodechlorination of dichloromethane by bimetallic Cu/Al particles
Journal
Chemical Engineering Journal
Journal Volume
273
Pages
413-420
Date Issued
2015
Author(s)
Abstract
Vitamin B12-mediated hydrodechlorination was carried out to effectively transform dichloromethane (DCM) to methane with bimetallic copper/aluminum (Cu/Al) particles. DCM is known as a recalcitrant chlorinated organic contaminant unable to be degraded by many reductive technologies including zero-valent iron (ZVI), bimetallic palladium/iron (Pd/Fe) nanoparticles, and many other zero-valent metals. Cu/Al bimetal is a low-cost and high effective reactive material. Unlike expensive borohydride-synthesized copper nanoparticles, Cu/Al bimetal particles prepared by reduction of cupric ion using zero-valent aluminum offers high surface areas (>100m2g-1) and strong reducing conditions at a low cost. In this study, though the degradation of DCM by Cu/Al alone was relatively slow, an order of magnitude increase in reaction rates was observed when vitamin B12 was added into the Cu/Al reaction system. Approximately 98% of the DCM was degraded rapidly within 2h by Cu/Al and vitamin B12. Reaction mechanisms of DCM degradation in this B12-Cu/Al system were proposed. UV/Visible spectra showed that vitamin B12 (Co(III)) was reduced to vitamin B12r (Co(II)) without further reduction to vitamin B12s (Co(I)) in the presence of Cu/Al. A synergistic effect of copper and vitamin B12 facilitating the carbon-chlorine (C-Cl) bond scission on the copper surface enhanced the reductive dechlorination of DCM.
SDGs
Type
journal article