Strained Ni-WC nano-islands by localized accelerated carbonization emulate noble-metal RWGS activity

Area of Science:

• Catalysis
• Materials Science
• Environmental Chemistry

Background:

• The reverse water-gas shift (RWGS) reaction is key for converting CO2 into valuable CO.
• Developing stable and selective non-noble metal catalysts for RWGS is challenging.
• Existing catalysts often lack the required performance for industrial CO2 utilization.

Purpose of the Study:

• To engineer a high-performance, non-noble metal catalyst for the RWGS reaction.
• To investigate a novel Ni site-induced localized accelerated carbonization process.
• To create stable and selective Ni-WC nano-islands for CO2-to-CO conversion.

Main Methods:

• Synthesis of Ni-WC nano-islands on a WO2 support via a localized accelerated carbonization process.
• Characterization using in-situ DRIFTS and Raman spectroscopy.
• Density Functional Theory (DFT) calculations to understand reaction mechanisms.

Main Results:

• The Ni0.02WC/WO2-NIs catalyst achieved a CO production rate of 2340 molCO·molWC−1·h−1 with >97% CO selectivity.
• The catalyst demonstrated exceptional stability, with only 0.5% activity loss after 100 hours at 500°C.
• DFT and spectroscopic studies revealed synergistic effects at WC/WOx interfaces, enhancing CO2 reduction.

Conclusions:

• Ni-WC nano-islands, formed through a localized carbonization process, exhibit noble metal-like activity for RWGS.
• The unique nano-island structure and interface synergy are crucial for high CO2 conversion efficiency and selectivity.
• This approach offers a promising strategy for designing advanced catalysts for CO2 valorization and emission mitigation.