[email protected]/C with Controllable Pd Dispersion as a Highly Efficient Catalyst for Hydrogen Evolution from Ammonia Borane
Henan Key Laboratory of Function-Oriented Porous Materials, College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471934, China
College of Food and Drug, Luoyang Normal University, Luoyang 471934, China
School of Chemistry and Material Science, College of Chemistry, Chemical Engineering and Environmental Engineering, Liaoning Shihua University, Fushun 113001, China
Authors to whom correspondence should be addressed.
Nanomaterials 2020, 10(9), 1850; https://doi.org/10.3390/nano10091850
Received: 19 August 2020 / Revised: 11 September 2020 / Accepted: 14 September 2020 / Published: 16 September 2020
(This article belongs to the Special Issue New Frontiers in Metal Nanoparticles for Heterogeneous Catalysis)
A series of [email protected]/C with different Pd contents was prepared using the galvanic reduction method to disperse Pd on the surface of Cu nanoparticles on Cu/C. The dispersion of Pd was regulated by the Cu(I) on the surface, which was introduced by pulse oxidation. The Cu2O did not react during the galvanic reduction process and restricted the Pd atoms to a specific area. The pulse oxidation method was demonstrated to be an effective process to control the oxidization degree of Cu on Cu/C and then to govern the dispersion of Pd. The catalysts were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscope (HRTEM), high angular annular dark field scanning TEM (HAADF-STEM), energy-dispersive spectroscopy (EDS) mapping, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), auger electron spectroscopy (AES), and inductively coupled plasma optical emission spectrometer (ICP-OES), which were used to catalyze the hydrogen evolution from ammonia borane. The [email protected]/C had much higher activity than the PdCu/C, which was prepared by the impregnation method. The TOF increased as the Cu2O in Cu/C used for the preparation of [email protected]/C increased, and the maximum TOF was 465 molH2 min−1 molPd−1 at 298 K on [email protected]0.5/C-640 (0.5 wt % of Pd, 640 mL of air was pulsed during the preparation of Cu/C-640). The activity could be maintained in five continuous processes, showing the strong stability of the catalysts.