The development of highly efficient metal-free carbon electrocatalysts for the oxygen reduction reaction (ORR) is one very promising strategy for the exploitation and commercialization of renewable and clean energy,but this still remains as ignificant challenge.H erein, we demonstrate afacile approach to prepare three-dimensional (3D) N-doped carbon with as p 3 /sp 2 carbon interface derived from ionic liquids via as imple pyrolysis process.T he tunable hybrid sp 3 and sp 2 carbon composition and pore structures stem from the transformation of ionic liquids to polymerizedo rganics and introduction of aC om etal salt. Through tuning both composition and pores,t he 3D N-doped nanocarbon with ah igh sp 3 /sp 2 carbon ratio on the surface exhibits as uperior electrocatalytic performance for the ORR compared to that of the commercial Pt/C in Zn-air batteries.D ensity functional theory calculations suggest that the improved ORR performance can be ascribed to the existence of Ndopants at the sp 3 / sp 2 carbon interface,w hichc an lower the theoretical overpotential of the ORR.

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In comparison to the traditional petroleum-based plastics, polylactic acid, the most popular biodegradable plastic, can be decomposed into carbon dioxide and water in the environment. However, the natural degradation of polylactic acid requires a substantial period of time and, more importantly, it is a carbon-emitting process. Therefore, it is highly desirable to develop a novel transformation process that can upcycle the plastic trash into value-added products, especially with high chemical selectivity. Here we demonstrate a one-pot catalytic method to convert polylactic acid into alanine by a simple ammonia solution treatment using a Ru/TiO2 catalyst. The process has a 77% yield of alanine at 140 °C, and an overall selectivity of 94% can be reached by recycling experiments. Importantly, no added hydrogen is used in this process. It has been verified that lactamide and ammonium lactate are the initial intermediates and that the dehydrogenation of ammonium lactate initiates the amination, while Ru nanoparticles are essential for the dehydrogenation/rehydrogenation and amination steps. The process demonstrated here could expand the application of polylactic acid waste and inspire new upcycling strategies for different plastic wastes.