One-Pot Thermal Plasma Synthesis of Hybrid Nanostructures with Ni NPs on BNNT Surface for Stable and Efficient Catalytic Ammonia Decomposition

Abstract

A hybrid nanomaterial comprising Ni nanoparticles (NPs) grown on the outer walls of boron nitride nanotubes (BNNTs) was synthesized using a one-pot, in situ, mass-production thermal plasma method. The Ni/BNNT nanomaterial, with Ni NPs separately distributed on BNNT surfaces, preserved the hollow tubular structure of BNNTs and the catalytic activity of Ni NPs. Morphological, structural, and compositional analyses revealed well-crystallized Ni NPs, averaging less than 6 nm in diameter and accounting for 30% of the volume concentration, on BNNT surface. At a gas hourly space velocity of NH₃ of 12,820 mL g^–1h^–1, Ni/BNNTs achieved 100% NH₃ conversion at 750 °C with an apparent activation energy of 71.4 kJ mol^–1. Additionally, a 100 h long-term NH₃ decomposition test demonstrated the excellent thermal stability of Ni/BNNTs, with no aggregation of Ni NPs or loss of catalytic performance. This study presents a promising synthesis pathway for metal NP/BNNT hybrids suitable for high-temperature catalytic applications, offering superior stability, sintering resistance, and enhanced dispersibility.