Nickel(0) nanoparticles supported on bare or coated cobalt ferrite as highly active, magnetically isolable and reusable catalyst for hydrolytic dehydrogenation of ammonia borane

Joydev Manna; Serdar Akbayrak; Saim Özkar

doi:10.1016/j.jcis.2017.08.045

Nickel(0) nanoparticles supported on bare or coated cobalt ferrite as highly active, magnetically isolable and reusable catalyst for hydrolytic dehydrogenation of ammonia borane

J Colloid Interface Sci. 2017 Dec 15:508:359-368. doi: 10.1016/j.jcis.2017.08.045. Epub 2017 Aug 16.

Authors

Joydev Manna¹, Serdar Akbayrak², Saim Özkar³

Affiliations

¹ Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey.
² Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey; Department of Chemistry, Faculty of Arts and Science, Sinop University, 57000 Sinop, Turkey. Electronic address: serdarakbayrak.rg@gmail.com.
³ Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey. Electronic address: sozkar@metu.edu.tr.

PMID: 28843925
DOI: 10.1016/j.jcis.2017.08.045

Abstract

Nickel(0) nanoparticles supported on cobalt ferrite (Ni⁰/CoFe₂O₄), polydopamine coated cobalt ferrite (Ni⁰/PDA-CoFe₂O₄) or silica coated cobalt ferrite (Ni⁰/SiO₂-CoFe₂O₄) are prepared and used as catalysts in hydrogen generation from the hydrolysis of ammonia borane at room temperature. Ni⁰/CoFe₂O₄ (4.0% wt. Ni) shows the highest catalytic activity with a TOF value of 38.3min^-1 in hydrogen generation from the hydrolysis of ammonia borane at 25.0±0.1°C. However, the initial catalytic activity of Ni⁰/CoFe₂O₄ catalyst is not preserved in subsequent runs of hydrolysis. Coating the surface of cobalt ferrite support with polydopamine or silica leads to a significant improvement in the stability of catalysts. The TOF values of Ni⁰/PDA-CoFe₂O₄ and Ni⁰/SiO₂-CoFe₂O₄ are found to be 7.6 and 5.3min^-1, respectively, at 25.0±0.1°C. Ni⁰/PDA-CoFe₂O₄ catalyst shows high reusability as compared to the Ni⁰/CoFe₂O₄ and Ni⁰/SiO₂-CoFe₂O₄ catalysts in hydrolytic dehydrogenation of ammonia borane at room temperature. All the catalysts are characterized by using a combination of various advanced analytical techniques. The results reveal that nickel nanoparticles with an average size of 12.3±0.7nm are well dispersed on the surface of PDA-CoFe₂O₄. .

Keywords: Ammonia borane; Cobalt ferrite; Magnetic support; Nickel(0) nanoparticles; Polydopamine/silica coating.