Can e-waste be a resource to prepare useful catalysts? - A review

Electronic and electrical devices have become indispensable due to their dominance in every sector, i.e., from the kitchen to transportation. Despite the invaluable contribution, the use of electronic and electrical devices leads to the accumulation of a massive amount of electronic waste (e-waste), which in turn causes environmental pollution and geopolitical issues. Out of 62 million tons of e-waste released during 2022, only 22% was recycled, underlining the importance of new strategies to tackle this e-waste. As e-waste materials contain valuable metals like copper and gold, they could be utilized as potential metallic sources. Therefore, extracting these metals from e-waste and subsequently utilizing them as catalysts in diverse chemical reactions has become vibrant. Intriguingly, this would reduce the cost of chemicals, which are prepared using catalysts, in addition to tackling environmental pollution. Considering the importance of e-waste as a potential resource for preparing catalysts, this review attempts to discuss the catalysts recovered from e-waste and their applications in various chemical transformations. The types of e-waste materials have been explained at the outset to understand their composition, especially the metals. Next, gold- and copper-based catalysts derived from e-waste have been discussed due to their excellent catalytic properties. A special emphasis is given to the catalysts derived from the e-waste of spent Li-ion batteries, considering their rapid growth, safety concerns, and metal content. The other possible catalysts prepared from e-waste have also been reviewed before the conclusion.