In situ nanoconfinement catalysis for rapid hydrodechlorination of chlorophenol

Abstract

Chlorinated phenols are highly toxic to human and ecosystem and their biological degradation is difficult. In this work, a novel MgAlNi alloy catalyst was developed for rapid chemical degradation of p-chlorophenol (4-CP) in water under mild conditions via in situ hydrodechlorination (iHDC) without external hydrogen gas supply. A complete conversion of 0.195 mM 4-CP to phenol was achieved within 15 min with a reaction rate constant of 7.65 h⁻¹, 19.4 times higher than that of the traditional Raney Nickel (AlNi alloy) catalyst. The excellent performance of MgAlNi alloy catalyst is attributed to enhanced H₂ generation by Mg etching, surface self-reconstruction by growth of in situ layered double hydroxide (iLDH) nanosheets of 0.08–1 nm, exposed active sites of AlNi intermetallic compounds Al₃Ni₂ and Al₃Ni. The findings of this study provide new insights into broader applications of nanoconfinement catalysis to environmental remediation and open a new domain of in situ nanoconfinement catalysis (iNCC).