Improved catalytic effect and metal nanoparticle stability using graphene oxide surface coating and reduced graphene oxide for hydrogen generation from ammonia–borane dehydrogenation

Abstract

The development of high catalytic effective catalysts for hydrogen generation through dehydrogenation (hydrolysis) of aqueous NH₃BH₃ (AB) solution is discussed in this work. Bimetallic NiPt, CoPt and monometallic Ni, Co, Pt nanoparticles (NPs) supported on mixed graphene oxide (GO) and reduced graphene oxide rGO (carbon materials) were produced and studied for hydrogen generation from AB hydrolytic dehydrogenation. Herein, we have developed fine, spherically-shaped bimetallic and monometallic Ni, Co, Pt NPs on mixed GO and rGO for extremely high reactant productivity in aqueous AB hydrolysis. The Co_0.8Pt_0.2/GO and rGO, Ni_0.8Pt_0.2/GO and rGO catalysts show high catalytic performance and high turnover frequency (TOF) of 230.76 and 214.28 (H₂) mol. (cat. metal) mol⁻¹ min⁻¹ at 25 °C. This is the greatest efficiency ever shown for transition metal-doped GO and rGO catalysts. The catalysts additionally show superior catalytic stability by maintaining up to 98% activity after 7 runs at 25 °C. The development of well-organized and inexpensive Co_0.8Pt_0.2/GO and rGO, Ni_0.8Pt_0.2/GO and rGO catalysts improve the possibility of using aqueous AB as chemical hydrogen storage. This permits the discovery of additional hydrogen fuel-cell applications. The simple and facile production of other GO and rGOs can assist in transition metal NPs.