Trimetallic Catalyst Boosts Climate Action

The Discovery

The study introduces a trimetallic catalyst—comprising nickel (Ni), copper (Cu), and zinc (Zn) nanoparticles supported on defective ceria (CeO₂)—that achieves unprecedented performance in CO₂ reduction. The catalyst demonstrated:

• CO Productivity: An astounding 49,279 mmol g⁻¹ h⁻¹ at 650°C, a nine-fold increase over previously reported catalysts.
• CO Selectivity: Up to 99%.
• Stability: Maintained performance for at least 100 hours without degradation.

The catalyst's extraordinary efficiency is attributed to the creation of a Strong Metal-Support Interaction (SMSI) between the trimetallic sites and the defective ceria. This unique interaction fine-tunes the electronic structure, enabling optimal performance.

Unveiling the Mechanism

This research relied heavily on advanced in-situ techniques and a multidisciplinary collaboration:

1. In-Situ HERFD-XANES at ESRF, France

   Dr. Pieter Glatzel and the team at the European Synchrotron Radiation Facility (ESRF), Grenoble, played a pivotal role in uncovering the electronic dynamics of the system. High-energy-resolution fluorescence-detection X-ray absorption spectroscopy (HERFD-XAS) revealed how SMSI alters oxidation states and electron density distribution across the catalyst.

2. In-Situ TEM and EELS at Ernst-Ruska Center, Germany

   Dr. Paul Paciok from the Ernst-Ruska Center, Germany, contributed critical insights through in-situ transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). These studies visualized, for the first time, the growth and movement of trimetallic sites under catalytic conditions. Once SMSI was established, the movement ceased, preventing further diffusion or sintering.

3. Molecular Understanding via DFT at IIT Bombay, India

   Prof. Ojus Mohan's group at IIT Bombay utilized density functional theory (DFT) calculations to unravel the reaction mechanism. The studies highlighted how reaction intermediates form and convert into products, driven by a complex interplay of direct dissociation and redox pathways on different active sites.

Why It Matters

The conversion of CO₂ to CO is a critical step in transforming carbon dioxide into value-added chemicals and fuels. However, commercial viability has been hindered by low productivity, poor selectivity, and instability of existing catalysts. By leveraging SMSI and defect engineering, this study has overcome these barriers, setting new benchmarks in CO₂ reduction catalysis.

This research not only provides a highly effective catalyst for CO₂ conversion but also offers a blueprint for designing next-generation catalysts through precise electronic structure tuning and defect manipulation.

Future Implications

These findings open new avenues for the development of advanced catalysts for CO₂ utilization and other critical chemical transformations. As Prof. Polshettiwar states, "By combining traditional catalytic materials with cutting-edge defect engineering and SMSI, we've shown how to address fundamental limitations in catalysis. The study offers a roadmap for designing advanced catalysts and demonstrates the impact of integrating traditional materials with cutting-edge approaches, offering hope for a sustainable future.