Structured nickel catalysts for sodium borohydride hydrolysis (SBH) were synthesized by surface modification of nickel foam. The fabrication process consisted of i) nickel aluminization, ii) post-annealing, and iii) selective aluminum leaching. Through low-temperature chemical alloying, nickel was aluminized at 400 °C, and a 0.5 μm-thick NiAl3 alloy outer-layer was formed. While discontinuing the influx of the aluminum source, post-annealing was conducted to transform the NiAl3 outer-layer into different Ni–Al alloys, such as NiAl3 on Ni2Al3, Ni2Al3 on NiAl, and NiAl on Ni3Al at 400, 500, and 600 °C, respectively. After the selective aluminum leaching, the surface treatment increased the surface area by factors of 2.2–77.1, leading to a significant enhancement of activity in SBH hydrolysis. Additionally, the catalyst undergoing post-annealing at 400 °C achieved superior performance in both initial activity and durability, due to the adhesion layer of Ni2Al3 formed between the outermost catalytic layer and the nickel substrate. Finally, continuous SBH-based hydrogen generation using the catalyst with post-annealing at 400 °C was achieved and the as-developed nickel catalyst produced hydrogen at a rate of up to 400 ± 27 sccm/gcatalyst while exhibiting excellent durability for 3 h.
|Journal||Journal of Alloys and Compounds|
|Publication status||Published - 2020 Nov 30|
Bibliographical noteFunding Information:
This work was supported by the Hydrogen Energy Innovation Technology Development Program of the National Research Foundation of Korea (NRF) funded by the Korean government (Ministry of Science and ICT [MSIT] ) (No. NRF-2019M3E6A1064611 ) as well as Korea Institute of Science and Technology (KIST) institutional program (No. 2E30202 ).
© 2020 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry