Engineering hydroxyls on a metal-organic framework as Adsorbers and high-activity Dehydrochlorination sites for selective gold recovery

Design of stable materials for selective gold extraction from complex sources is of a great challenge due to the poor understanding of the fundamental conversion processes responsible for anionic gold. Herein, engineering terminal hydroxyls is reported to tune the interfacial adsorption of aqueous [AuCl4]−. The energetically favorable nucleation pathway endorses the conversion of [AuCl4]− to Au atoms on the adsorption sites by dehydrochlorination, forming polyhedral Au particles anchored on the Zr6OH-BTC. Compared to the atomically separated adsorption, this terminal hydroxyl‑assisted approach achieved 5.7 times enhancement in the gold recovery capacity. This study paves a new way to comprehend the conversation and adsorption mechanism for alleviating the emerging dilemma of gold recovery.