Atomically Dispersed Zn-Stabilized Ni^δ+ Enabling Tunable Selectivity for CO₂ Hydrogenation

Area of Science:

• Heterogeneous catalysis
• Materials science
• Chemical engineering

Background:

• Catalyst performance enhancement via elemental modification is crucial for industrial processes.
• Understanding the mechanism of secondary elements is key for rational catalyst design.
• Nickel-based catalysts are widely used but require optimization for specific reactions.

Purpose of the Study:

• To investigate the effect of introducing zinc (Zn) as a second element into Ni/ZrO2 catalysts for carbon dioxide (CO2) hydrogenation.
• To elucidate the enhanced catalytic mechanism induced by Zn modification.
• To provide insights for designing more efficient heterogeneous catalysts.

Main Methods:

• Synthesis of Ni/ZrO2 and NiZn/ZrO2 catalysts.
• Performance evaluation through CO2 hydrogenation reactions.
• Structural characterization using advanced techniques (e.g., X-ray diffraction, spectroscopy).

Main Results:

• NiZn/ZrO2 catalysts exhibited a significant shift in selectivity from methane (CH4) to carbon monoxide (CO) compared to Ni/ZrO2.
• Zn was found to be atomically dispersed, forming NiZnO x and ZnZrO x species.
• Zn stabilized a higher valence state of Ni (Niδ+) at the Ni-O-Zn active site, promoting CO generation.

Conclusions:

• The introduction of Zn into Ni/ZrO2 catalysts creates an O-mediated bimetallic effect.
• The Ni-O-Zn active site is responsible for the enhanced selectivity towards CO.
• This study offers new insights into the rational design of advanced heterogeneous catalysts for CO2 conversion.