From Mobile Phones to Catalysts: E-Waste-Derived Heterogeneous Copper Catalysts for Hydrogenation Reactions

Abstract

Electronic waste or E-waste, produced from end-of-life electronic equipment, is the fastest growing solid waste stream, and its rapid generation creates significant environmental problems on a global scale. E-waste contains valuable metals in much higher concentrations than their respective primary resourcesmetal ores. Currently, less than a quarter of all E-waste is being recycled to recover precious metals; thus, most of the waste is being exported to developing countries, where it is often landfilled and stockpiled. Poor treatment of this hazardous waste causes environmental damage and poses serious health risks to inhabitants in these areas. Therefore, the development of new strategies for the recovery and valorization of metals from E-waste is of increasing importance. In this paper, we describe a methodology for converting E-waste to useful catalytic materials while producing gold-enriched solids as the byproduct. In particular, we report a copper-based heterogeneous catalyst (Cu-iKat) obtained from cellular and mobile phone printed circuit boards (PCBs) via precipitation/deposition of PCB metal leachate on an inert γalumina support. This Cu-iKat was characterized by powder X-ray diffraction (XRD), high-resolution X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and its catalytic activity was demonstrated on hydrogenation of ketones and N-heterocycles. Moreover, Cu-iKat can be used for deoxygenation of benzyl alcohols and hydrogenolysis of formamides to amines and methanol.

Direct Reuse of Spent Lithium-Ion Batteries as an Efficient Heterogeneous Catalyst for the Reductive Upgrading of Biomass-Derived Furfural

“…Only few attempts are present in the literature on the valorization of e-waste as heterogeneous catalytic systems, most of which require the prior recovery of active metals. − In this study, we present a simple protocol for the conversion of black mass into a stable and efficient heterogeneous Co-based catalyst for the selective reductive upgrading of biomass-derived molecules thus paving the way for a new reuse of spent LIBs.…”

Cu nanoparticles embedded on reticular chitosan-derived N-doped carbon: Application to the catalytic hydrogenation of alkenes, alkynes and N-heteroarenes

“…Overall, considering previous studies applying copper/Al2O3 heterogeneous catalysts to the hydrogenation of N-heterocycles [58,59], the present catalyst operates at a rather high copper loading (9.2 mol%) then previously reported (2.5 mol%). The reactions require higher hydrogen pressures and longer reaction times to be effective (50 bar H2 and 13-84 h versus 40 bar H2 and 24 h), leading to lower turnover frequencies (TOF between 0.02-0.83 h -1 versus 1.50-1.70 h -1 ).…”

Challenges and Opportunities in the Management of Electronic Waste and Its Impact on Human Health and Environment

“…The selection of the optimal process may also depend on the targeted fuel nature; hydrogen, oil, or direct heat [128,135]. Regarding the processes that are used to recycle e-waste or convert it into useful materials, they are difficult to compare in terms of their greenness and efficacy because they can be physical, chemical, or biological, and operate at different severities and target different products [137][138][139].…”