Polydopamine-coated halloysite nanotubes supported AgPd nanoalloy: An efficient catalyst for hydrolysis of ammonia borane

Abstract

AgPd alloy nanoparticles (NPs) supported on halloysite nanotubes (HNTs) coated polydopamine (PDA) successfully synthesized by one-pot hydrothermal route. XRD, TEM and XPS were employed to verify the alloy structure of the obtained AgPd NPs. The HAADF-STEM result revealed that the thickness of PDA coating was ∼10 nm, which could be formed on the surface of HNTs, and the existence of PDA was beneficial to deposit AgPd alloys with high dispersibility on the surface of HNTs. AgPd/PDA-HNT nanocomposites were effective catalysts for the hydrolysis of ammonia borane at room temperature, and the reaction was completed within 160 s using Ag3Pd2/PDA-HNT as catalysts, with a high total turnover frequency (TOF) value of 90 molH2 molcatalyst−1 min−1 and a low apparent activation energy (Ea) of 22.7 kJ mol−1. After the sixth cycle, Ag3Pd2/PDA-HNT catalyst retained 72% of its initial activity and 100% conversion. The excellent catalytic properties, good durability and reusability, enabled Ag3Pd2/PDA-HNT to be an ideal catalyst in the practical applications.