Effect of Transition Metals Addition on the Nickel Oxide Catalyst Toward Reduction Behaviour in Carbon Monoxide Atmosphere

• Published in: Pertanika Journal of Science and Technology
• Main Author: Dzakaria N.; Lahuri A.H.; Salleh F.; Saharuddin T.S.T.; Samsuri A.; Yarmo M.A.
• Format: Article
• Language: English
• Published: Universiti Putra Malaysia Press 2023
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85164171639&doi=10.47836%2fpjst.31.4.07&partnerID=40&md5=1a409edc28455f1344cbc92b7a9acc6a

The chemical reduction progression behaviour of transition metals (Mo, Zr, W, Ce, and Co) doped on NiO was studied using temperature programmed reduction (TPR) analysis. A wet impregnation method was applied to synthesise the doped NiO series catalysts. The reduction progress of the catalysts was attained by using a reductant gas at the concentration of 40% v/v CO/N2. X-ray diffraction (XRD) was employed to determine the composition of the reduced phases. Undoped NiO was reduced at 384℃ to obtain a cubic phase of NiO. It was observed that Ce/NiO exhibited the lowest reduction temperature of 370℃ among all catalysts. This phenomenon might be due to a higher surface area of Ce/NiO compared to undoped NiO, which facilitated a faster reduction reaction. The rest of the doped NiO series catalysts (Co/NiO, Mo/ NiO, W/NiO and Zr/NiO) demonstrated a higher reduction temperature compared to undoped NiO. New peaks in the XRD pattern were observed only for the reduced catalysts of Mo/NiO and W/NiO, which were associated with monoclinic MoO2 and WO2.72 phases, respectively. The formation of new compounds or more stable nickel alloys led to a slower reduction reaction than undoped NiO. Therefore, Ce/NiO was the most efficient catalyst in promoting the formation of Ni under the CO atmosphere. © Universiti Putra Malaysia Press.