Influence of the Water/Titanium Alkoxide Ratio on the Morphology and Catalytic Activity of Titania–Nickel Composite Particles for the Hydrolysis of Ammonia Borane

Abstract

This work reports the influence of the water/titanium alkoxide ratio during the preparation of titania–nickel composite particles on their morphology and catalytic activity toward the hydrolysis of ammonia borane. The titania–nickel composite particle catalysts were fabricated by using a sol‐gel method, followed by an activation process in aqueous solution containing sodium borohydride and ammonia borane. From the scanning electron microscopy images and pore‐size distributions calculated from nitrogen sorption data, the particle dispersion was significantly enhanced at ratios above 6000, and increased with increasing water/titanium alkoxide ratio. Stoichiometric amounts of hydrogen were evolved in the presence of all of the prepared titania–nickel composite particle catalysts. The particle dispersion influenced the hydrogen evolution rate from aqueous ammonia borane solution, and the samples with the most highly dispersed particles showed the highest hydrogen evolution rate. The most active catalyst showed an apparent activation energy comparable to that of other reported catalysts and high cycle ability for the hydrolysis of ammonia borane.

Oxygen-Evolution Activity of p–n Heterojunction NiO–SnO2 Ceramic on Ti Substrate Fabricated Using a Simple Layer-by-Layer Method

“…38 Simultaneously, the weak adsorption bands at 640−660 nm and the strong absorption bands at 700−750 nm were assigned to the octahedral coordination of Ni 2+ . 39,40 In the UV region, the absorption bands of NSCT-480 were different from those of NSCT-600. The DRUV−vis spectra of NSCT-480 displayed peaks centered at 270 nm, which were associated with hexa-coordinated polymeric Sn−O−Sn species.…”

Highly Active Nickel (II) Oxide-Supported Cerium Oxide Catalysts for Valorization of Glycerol into Oxygenated Fuel Additives

“…Moreover, the peak intensity increases with the quantity of NiO impregnated, and this signal can be associated with the Ni-O charge transfer transition [ 45 ]. In addition, the 9NiO/CeO 2 , 27NiO/CeO 2 , and 45NiO/CeO 2 exhibit a new and broad signal centered at 725 nm, which is attributed to the electronic transition of octahedrally coordinated Ni 2+ ions from the 3 A 2g (F) → the 3 T 1g (F) state [ 46 , 47 ]. This band is stronger for 45NiO/CeO 2 , followed by 27NiO/CeO 2 and 9NiO/CeO 2 .…”