# La2–x Sr x Ce2–y Ni y O7 Catalysts with Interstitial Nickel for Enhanced Dry Reforming of Methane

## TL;DR

This study develops a new nickel-doped oxide catalyst that improves the efficiency of converting methane and carbon dioxide into hydrogen and carbon monoxide.

## Contribution

The paper introduces a defect-engineered oxide catalyst with interstitial nickel for enhanced dry reforming of methane.

## Key findings

- The catalyst La1.9Sr0.1Ce1.7Ni0.3O7 achieved over 70% conversion of CO2 and CH4 at 700°C.
- Minimal coke deposition was observed due to the oxidative dissociation pathway of methane.
- Metal–support interactions and electron transfer from Ni to Ce improved catalytic performance.

## Abstract

This study explores the catalytic performance of solution
combustion-synthesized
doped defective fluorite catalysts, La2–

x
Sr
x
Ce2–

y
Ni
y
O7, for the dry reforming of methane. A comprehensive structural
analysis, supported by theoretical calculations, revealed that the
adopted synthetic methodology enabled Ni doping beyond a critical
concentration, leading to its occupation of the interstitial lattice
sites. The optimally doped Ni-containing defective fluorite oxide
La1.9Sr0.1Ce1.7Ni0.3O7 exhibited superior catalytic activity with more than 70%
conversion of CO2 and CH4 with an H2/CO ratio of 0.7 for a 50-h reaction at 700 °C. The prolonged
reforming reaction also resulted in minimal coke deposition (11 μgc gcat
–1 h–1), primarily due to the oxidative dissociation pathway of methane,
as revealed through mechanistic analysis. Detailed surface studies
highlighted the crucial role of metal–support interactions,
wherein facile electron transfer from Ni to Ce during the reaction
contributed significantly to the enhanced catalytic performance. Thus,
this study establishes a strategic framework for designing and developing
defect-engineered oxide catalysts, paving the way for advanced materials
in dry methane reforming.