# Selective Reduction of CO2 to CO via the RWGS Reaction over ZnO-ZrO2-Ga2O3-Supported Catalysts Modified with Keggin-Type Heteropolyacid Precursors

## TL;DR

This paper explores how to efficiently convert CO2 into CO using modified catalysts at low temperatures.

## Contribution

The study introduces Mo/ZZG catalysts with Keggin-type heteropolyacid precursors for efficient CO2 reduction.

## Key findings

- Mo/ZZG catalysts showed excellent activity in the RWGS reaction at low temperatures.
- These catalysts had the lowest activation energy and highest CO2 conversion efficiency.
- Characterization techniques revealed strong links between structure and performance.

## Abstract

Mo/ZZG and W/ZZG nanomaterials for the catalytic reduction of CO2 were successfully prepared from preformed ZnO-ZrO2-Ga2O3 (ZZG) and HPMo and HPMo heteropolyacids via simple incipient wetness impregnation. To establish the relationship between structural properties and catalytic performance, the prepared catalysts were deeply characterized using XRD, Raman spectroscopy, SEM coupled with EDX, BET, XPS, and H2-TPR techniques. The catalytic performance of the materials was evaluated in the RWGS reaction under atmospheric pressure, using a feed composition of CO2/H2/N2 = 1/3/1 across a temperature range of 250–600 °C. All materials were active in the reverse water gas shift reaction (RWGS) under these conditions, with the Mo/ZZG catalyst exhibiting the best performance, demonstrating excellent catalytic activity at low temperature with the lowest activation energy and the highest CO2 to CO conversion efficiency.