Copper Based Bi‐, and Trimetallic Nanoparticles as Efficient Catalysts for Dehydrogenation of Sodium Borohydride

ABSTRACT

The mono‐metallic (Ag ⁰ , Cu ⁰ , and Pt ⁰ ), bi‐metallic (Cu ⁰ /Ag ⁰ and Cu ⁰ /Pt ⁰ ) and tri‐metallic (Cu ⁰ /Ag ⁰ /Pt ⁰ , Pt ⁰ /Ag ⁰ /Cu ⁰ and Cu ⁰ /Pt ⁰ /Ag ⁰ ) nanomaterials were prepared by the chemical reduction method and used as the catalysts for the hydrogen generation from the dehydrogenation of sodium borohydride (NaBH ₄ ). The tri‐metallic Cu ⁰ /Ag ⁰ /Pt ⁰ , Pt ⁰ /Ag ⁰ /Cu ⁰ , and Cu ⁰ /Pt ⁰ /Ag ⁰ exhibit higher catalytic activities for the generation of hydrogen from the dehydrogenation of NaBH ₄ than those of mono‐ and bi‐metallic (Ag ⁰ , Cu ⁰ , Pt ⁰ , Cu ⁰ /Ag ⁰ , Ag ⁰ /Pt ⁰ , and Cu ⁰ /Pt ⁰ ) nanoparticles. The effect of tri‐metallic nanoparticle composition and temperature play key roles in the dehydrogenation of NaBH ₄ . The activation energies were determined to be 59.3, 55.4, and 52.5 kJ/mol, respectively, for Cu ⁰ /Pt ⁰ /Ag ⁰ , Pt ⁰ /Ag ⁰ /Cu ⁰ , and Cu ⁰ /Ag ⁰ /Pt ⁰ . The catalytic efficiency depends on the chemical identity, synergistic effect, electronic interactions, and plating order of metal compositions. The kinetic studies indicate that the catalytic dehydrogenation of NaBH ₄ by Cu ⁰ /Ag ⁰ /Pt ⁰ is first‐order with respect to [Cu ⁰ /Ag ⁰ /Pt ⁰ ] and [NaBH ₄ ]. The as‐prepared Cu ⁰ /Ag ⁰ /Pt ⁰ has a catalytically active surface and would be a promising catalyst for the dehydrogenation of NaBH ₄ .