Nickel-rich NiCeLaFeCo medium-entropy alloy nanoparticles on oxygen and nitrogen co-doped carbon supports for hydrogen production from toluene cracking

Abstract

Multi-metallic nanoparticles (MMNPs) attract people's attention due to their great potential in the application of energy storage, medicine, and catalysis. In this study, a simple in situ reduction method was developed to synthesize the NiCeLaFeCo and NiCeLaFeCu medium-entropy alloy (MEA) nanoparticles on nitrogen and oxygen co-doped carbon supports, with guanine and transition metal nitrates as the precursors. The prepared face-centered cubic (FCC) NiCeLaFeCo MEA nanoparticles have small particle sizes (average 21.1 nm) and medium mixing entropy (1.31 R). To extend the application of MEA nanoparticles, we have conducted a toluene cracking test regarding toluene conversion and hydrogen generation. The catalyst loaded with nickel-rich (~55.26%) MEA nanoparticles presented a high catalytic performance (over 80% conversion and 7293 ppm hydrogen generation) at 500 °C upon 2 h time-on-stream, and better catalytic performance (99% conversion and 78960 ppm hydrogen generation) at 400 °C with steam reforming. This study has provided a simple and convenient way to synthesize the functionalized carbon-based multi-metallic nanoparticles, and showed their excellent catalytic performance in the toluene cracking and hydrogen generation.