Ni Nanoparticles Supported on High Surface Area Carborundum for Enhanced Hydrogen Production by Ammonia Decomposition

Abstract

Ni nanocatalysts based on high surface area carborundum for the decomposition of ammonia to COx-free hydrogen are synthesized using a wet impregnation approach. The catalysts were characterized using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and H2-temperature-programmed reduction (TPR) methods. The Ni/SiC catalyst was found to be extremely active for the decomposition reaction when their activities were assessed in a fixed-bed reactor. Ni content and calcination temperature affect the crystallite size, dispersion, and reducibility of Ni species, thereby impacting the catalytic properties of catalysts. The 30Ni/SiC catalyst demonstrates the highest catalytic activity and long-term stability. At a high space velocity of 30 000 mL gcat–1 h–1, the 30Ni/SiC-700 catalyst converts ammonia by 79.6% at 550 °C, demonstrating that Ni/SiC is an effective ammonia decomposition catalyst. The present study provides a promising avenue for the development of cost-effective and high-performance catalysts for hydrogen production via NH3 decomposition.