Structure-Sensitivity of CO2 Methanation over Nanostructured Ni Supported on CeO2 Nanorods

Eleonora Marconi,Simonetta Tuti,Igor Luisetto

doi:10.3390/catal9040375

Abstract

Ni-based oxides are widely investigated as catalysts for CO2 methanation due to their high activity, high selectivity and low cost. The catalytic performances of Ni-based catalysts depend on support properties that strongly influence the dispersion of the catalytic active phase and the Ni–support interaction. Although the CO2 methanation is widely studied, the structure sensitivity of methanation on nickel is not completely assessed. Ni/CeO2 nanorods with different nickel/ceria molar ratios (0.05, 0.10, 0.20, 0.30) were prepared by one-pot hydrothermal synthesis. The effect of nickel content and metal particle size on catalytic activity and selectivity for CO2 methanation were studied using CO2:H2 = 1:4 stoichiometric ratio at high space velocity (300 L g−1 h−1). Sample structure and morphology were studied by X-ray diffraction (XRD), Brunauer–Emmet–Teller (BET) analysis, field-emission scanning electron microscopy/energy-dispersive spectroscopy (FE-SEM/EDS), H2-temperature programmed reduction (TPR), H2-temperature-programmed desorption (TPD). Both the CO production and the turnover frequency appear depending on nickel particle size, suggesting a structure sensitivity of the CO2 methanation on nickel supported on ceria.

Highlights

Carbon dioxide is produced and released in industrial processes, energy production, biomass combustion and gasification, cement kilns and oil refinery
Analysis, field-emission scanning electron microscopy/energy-dispersive spectroscopy (FE-SEM/EDS), H2 -temperature programmed reduction (TPR), H2 -temperature-programmed desorption (TPD). Both the CO production and the turnover frequency appear depending on nickel particle size, suggesting a structure sensitivity of the CO2 methanation on nickel supported on ceria
(5–12 wt%) Ni/YSZ catalysts, we found a dependence of the activity for methanation on nickel particle size: smaller Ni0 particles were more active for CO formation instead of CH4 formation [5], and had anti-coking properties [6]

Summary

Introduction

Carbon dioxide is produced and released in industrial processes, energy production, biomass combustion and gasification, cement kilns and oil refinery. The hydrogenation of CO2 into chemicals or fuels like methane, methanol, dimethyl ether [4,5,6], or the reduction into syn-gas (CO and H2 ) by dry reforming with methane (DRM) [7,8,9,10] are interesting research fields of CO2 utilization. In the power-to-gas process (PtG) the intermittent excess of electricity, produced by renewable power sources like solar or wind, highly dependent on daytime, season and weather, is utilized to decompose water into hydrogen and oxygen by electrolysis [11,12]. The synthetic methane contributes to the reduction of greenhouse gas emissions, replacing the natural fossil methane

Methods

Results

Discussion

Conclusion