The Role of Strontium in CeNiO3 Nano-Crystalline Perovskites for Greenhouse Gas Mitigation to Produce Syngas.

Naushad Ahmad,Basel F Alrayes,Manawwer Alam,Fahad A Alharthi,Rizwan Wahab,Salim Manoharadas

doi:10.3390/molecules27020356

Abstract

The transition metal-based catalysts for the elimination of greenhouse gases via methane reforming using carbon dioxide are directly or indirectly associated with their distinguishing characteristics such as well-dispersed metal nanoparticles, a higher number of reducible species, suitable metal–support interaction, and high specific surface area. This work presents the insight into catalytic performance as well as catalyst stability of CexSr1−xNiO3 (x = 0.6–1) nanocrystalline perovskites for the production of hydrogen via methane reforming using carbon dioxide. Strontium incorporation enhances specific surface area, the number of reducible species, and nickel dispersion. The catalytic performance results show that CeNiO3 demonstrated higher initial CH4 (54.3%) and CO2 (64.8%) conversions, which dropped down to 13.1 and 19.2% (CH4 conversions) and 26.3 and 32.5% (CO2 conversions) for Ce0.8Sr0.2NiO3 and Ce0.6Sr0.4NiO3, respectively. This drop in catalytic conversions post strontium addition is concomitant with strontium carbonate covering nickel active sites. Moreover, from the durability results, it is obvious that CeNiO3 exhibited deactivation, whereas no deactivation was observed for Ce0.8Sr0.2NiO3 and Ce0.6Sr0.4NiO3. Carbon deposition during the reaction is mainly responsible for catalyst deactivation, and this is further established by characterizing spent catalysts.

Highlights

Among the various well-established CO2 conversion processes, such as electrochemical catalysis, photocatalysis, and thermal catalysis, methane reforming using carbon dioxide, commonly known as dry reforming of methane (DRM), has recently attracted scientists primarily because DRM converts major greenhouse gases, i.e., carbon dioxide and methane, to synthesize hydrogen and carbon monoxide, called synthesis gas, which is further utilized to produce liquid hydrocarbons [1,2,3,4,5,6,7,8]
The decomposition temperatures of CeNiO3 were relatively higher than strontiumincorporated Ce0.8Sr0.2NiO3 and Ce0.6Sr0.4NiO3
This study demonstrated the catalytic performance results of strontium-incorporated CexSr1−xNiO3 (x = 0.6–1) nanocrystalline perovskites for dry methane reforming

Summary

Introduction

Among the various well-established CO2 conversion processes, such as electrochemical catalysis, photocatalysis, and thermal catalysis, methane reforming using carbon dioxide, commonly known as dry reforming of methane (DRM), has recently attracted scientists primarily because DRM converts major greenhouse gases, i.e., carbon dioxide and methane, to synthesize hydrogen and carbon monoxide, called synthesis gas, which is further utilized to produce liquid hydrocarbons [1,2,3,4,5,6,7,8]. The DRM process plays a role in greenhouse gas mitigation and serves as a cause of climate change, and generates synthesis gas, a mixture of equimolar hydrogen and carbon monoxide suitable for the production of hydrocarbon via the well-known Fischer–Tropsch synthesis process [9,10,11,12,13]. It is well established that the proper choice and suitable design of a catalyst plays significant role in catalytic activity and stability during DRM [14,15,16]. Both noble metal-based and transition metal-based catalysts have been reported for DRM, but noble metal-based catalysts are expensive and less abundant despite their excellent catalytic activities [8]. The major challenge related to Ni-based catalysts is their deactivation during DRM, associated with sintering (which leads to loss of active metal surface area) and carbon deposition [21,22,23]

Methods

Results

Discussion

Conclusion