Sol-gel synthesis and application of NiO, NiTiO3 and Ni5TiO4(BO3)2 on open-cell TiO2 foams for CO2 methanation. (2nd February 2022)

• Record Type: Journal Article
• Authors: Heupel, Alwin; Suta, Kevin; Afflerbach, Sandra; Krumm, Wolfgang; Jiang, Xin; Hof, Felix; Streck, Philipp
• Is Part Of: Chemical engineering science. Volume 248:Part A(2022)
• Publication Date: 2022-02-02
• Subjects: Power-to-Methane -- Hydrogen storage -- CO2 methanation -- Open-cell foams -- Ni-TiO2 catalyst; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2021.117151
• Languages: English
• ISSNs: 0009-2509

Abstract

Graphical abstract: Highlights: Application of promising TiO2 open-cell foams as catalyst supports for methanation. Technical-scale sol–gel synthesis of catalysts NiO, NiTiO3 and Ni5 TiO4 (BO3 )2. Apparently promising needle-like Ni5 TiO4 (BO3 )2 is not applicable for methanation. Mixed NiO/NiTiO3 catalyst is active and stable despite low BET surface area. Lower calcination temperature and higher heating rate improve the activity. Abstract: Bottleneck of fixed-bed reactors for methanation in a Power-to-Methane (PtM) context is a reliable thermal-management due to the exothermic nature of the reaction under dynamic operation. Novel titania (TiO2 ) open-cell foam supports with promising heat, mass, and momentum transfer properties and Ni-based catalytic coatings are presented on a technical scale. The coating with promising catalyst candidates NiO, NiTiO3 and Ni5 TiO4 (BO3 )2 is conducted by a scalable sol–gel synthesis. Ni5 TiO4 (BO3 )2 is known as a promising tar removal catalyst, but shows no activity for the methanation reaction. Despite a low BET-surface area, high-loaded (57 wt% Ni) mixed-oxide NiO/NiTiO3 (∼57% NiO/∼43% NiTiO3 ) shows promising results. Adjusted activation with respect to high-temperature strong metal support interactions (SMSI) leads to a methane-yield close to equilibrium at 400 °C (CO2 conversion: 75%, CH4 selectivity: 99%). The catalyst is stable under realistic methanation conditions for at least 120 h of operation and outperforms an industrial catalyst (20 wt% Ni-Al2 O3 ) above 400 °C. This study reveals the underestimated potential that lies in transition metal-supported foam catalysts for direct methanation and is fundamental for further research regarding temperature control for dynamic PtM processes.