# Niδ+ Atoms Anchored In Situ on Ultrathin Ni‐Phyllosilicate Nanosheet Ensure High‐Efficient CO2 Reduction into CO at Moderate‐Low Temperature

## TL;DR

A new nickel-based catalyst efficiently converts CO2 into CO at moderate temperatures without producing methane, thanks to its unique structure.

## Contribution

A novel Niδ+-based catalyst design that breaks the activity-selectivity trade-off in CO2 reduction.

## Key findings

- The a-Niδ+-PSNS(400) catalyst achieves 92% CO selectivity with a formation rate of 21.0 mmolCO h⁻¹ gcat⁻¹.
- Low electron density of Niδ+ atoms prevents CO methanation, ensuring high CO selectivity.
- Ultrathin nanosheets enhance atom utilization and synergistic effects for improved catalytic performance.

## Abstract

Ni‐based catalysts are considered to be promising candidates for moderate‐low temperature (200−400 °C) reverse water‐gas shift (MLT‐RWGS) as an important CO2 reduction pathway. However, their high activation properties for CO inevitably lead to severe methanation at high CO2 conversion, creating an activity‐selectivity trade‐off and unsatisfactory CO yields. Here, a novel supported Ni‐based catalyst is deveolped, consisting of abundant Niδ+ atoms anchored in situ on ultrathin Ni‐phyllosilicate nanosheet (a‐Niδ+−PSNS(400), 0< δ ≤1). The a‐Niδ+−PSNS(400) break activity‐selectivity trade‐off and achieve high CO selectivity (92%) toward at a formation rate of 21.0 mmolCO h−1 gcat−1, outdistancing those of all prevailing Ni‐based catalysts for MLT‐RWGS. Such catalytic performance is attributed to unique geometric/electronic effects of a‐Niδ+−PSNS(400), i.e., exposed monodisperse Niδ+ atoms with low electron density on ultrathin Ni‐phyllosilicate nanosheet. The ultrathin nanosheet enables anchored Niδ+ atoms to fully expose and disperse, boosting atom‐utilization efficiency and atom‐synergistic effects, endowing them with high catalytic activity; while low electron density of Niδ+ atoms extremely weakens their chemical adsorption of CO, preventing further CO hydrogenation into CH4, which ensures their high CO selectivity. This work provides new insights into the design of active microstructures of high‐performance Ni‐based catalysts for synchronous high activity‐selectivity.

A novel supported Ni‐based catalyst, consisting of abundant Niδ+ atoms with low electron density anchored in situ on ultrathin Ni‐phyllosilicate nanosheet (a‐Niδ+−PSNS, 0< δ ≤1), achieve simultaneous outstanding CO2 conversion and CO selectivity. Their ultrathin nanosheet enables abundant anchored Niδ+ atoms to fully expose and disperse, which can efficiently reduce CO2 into CO and weakens the chemical adsorption of CO, preventing CO methanation.