Revisiting Pt foil catalysts for formamide electrosynthesis achieved at industrial-level current densities

Abstract

Current electrosynthesis catalysts typically rely on nanomaterial-based engineering with multi-dimensional structural modifications. However, such approaches may not always be necessary, especially for underexplored industrial electrochemical conversions. Here, we demonstrate that commercial platinum (Pt) foil catalysts excel in the electrochemical co-oxidation of waste polyethylene terephthalate (PET)-derived ethylene glycol (EG) and ammonia (NH3) into formamide (HCONH2), a process traditionally reliant on energy-intensive methods. This approach achieves a high Faradaic efficiency (FE) of 55.87 ± 1.4% and a productivity of 1003.63 ± 23.72 µmol cm−2 h−1 at industrially relevant current densities without any degradation for durable operation (more than 500 h and 300 h for H-cell and membrane electrode assembly (MEA) reactor, respectively). In situ spectroscopy, supported by theoretical calculations, suggests that *CH2O and *NH2 are likely key intermediates. Furthermore, the product sustainability index (ProdSI) and techno-economic analysis (TEA) underscore the cost-effectiveness and sustainability of noble Pt foil in this scenario, challenging the conventional reliance on complex electrocatalysts. This work provides distinctive insights into catalyst screening and demonstrates a viable strategy for upcycling waste plastics.