Improvement of Ni/Al2O3 Catalysts for Low-Temperature CO2 Methanation by Vanadium and Calcium Oxide Addition

Gabriella Garbarino,Paola Riani,Agnieszka Lewalska-Graczyk,Piotr Pieta,Wojciech Lisowski,Guido Busca,Paweł Kowalik,Katarzyna Antoniak-Jurak,Izabela S Pieta,Robert Nowakowski

doi:10.1021/acs.iecr.0c05556

Abstract

CO2 methanation is a very promising technology for the production of alternative fuels with the simultaneous use of greenhouse gases. Therefore, intensive research is carried out on the optimization of catalysts with excellent properties for operation in the area of low temperatures. Here, we present research on a catalyst composed of 19 wt % NiO supported on alumina/calcium aluminate. The catalyst was modified with V2O5 in order to be suited for extrusion and scale-up in the frame of power to gas technology. Samples with various vanadium contents (Ni–xV, where x represents the amount of vanadium) were prepared in the form of ground granules obtained from 0.5 mm diameter spherical grains. X-ray diffraction (XRD), transmission electron microscopy (TEM), skeletal infrared (IR), diffuse reflectance ultraviolet–visible-near-infrared (DR-UV–vis-NIR), and X-ray photoelectron (XPS) spectroscopies, as well as H2 temperature-programmed reduction (H2-TPR), were used to characterize the samples. Catalytic performances of the catalyst samples were tested in CO2 hydrogenation at 1 atm. Among the many supported Ni catalysts tested in our laboratories, the catalysts of 0.5 and 1 wt % V showed very high activity, with the highest CH4 yield of 97% at 623 K. These catalysts exhibited 100% CH4 selectivity up to 673 K. The excellent performances of the studied catalysts are attributed to the possible formation of Ni–V solid solution alloy nanoparticles.

Highlights

CO2 and CO methanation over nickel as a catalyst was first described by Sabatier and Senderens.[1,2] Since the mid-1960s, carbon oxides (COx) methanation has been used in the preparation of N2 + H2 ammonia synthesis gas to remove residual carbon oxides, usually at a very low concentration (
Calcium aluminates are reported to represent useful stabilizing supports for commercial extruded Ni-based catalysts to be used in steam reforming reactions (SR).[22−27] such stabilization has been proven in a pilot-test study applying both laboratory and industrial testing protocols.[23−27] We found that catalysts, which are primarily designed for both methane or biogas reforming, are active in CO2 methanation.[6,23−27] In this article, we report on the addition of vanadium oxide (V2O5) on the Ni/CaO− Al2O3 system in order to optimize the catalyst for CO2 methanation and improve its selectivity toward methane
The diffraction peaks at 37.5°, 39,7°, 46.7°, and 66.3° (2θ) of the alumina oxide phase corresponding to γ-Al2O3 (JCPDS 750921)[28] are mostly overlapped by calcite

Summary

Introduction

CO2 and CO methanation over nickel as a catalyst was first described by Sabatier and Senderens.[1,2] Since the mid-1960s, carbon oxides (COx) methanation has been used in the preparation of N2 + H2 ammonia synthesis gas to remove residual carbon oxides, usually at a very low concentration (

Methods

Results

Discussion

Conclusion