Lattice-Modulated Bi_0.1Ce_0.9O₂ Enabling Precise Intermediate Adsorption Tuning for H₂O₂ Electrosynthesis

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical hydrogen peroxide (H₂O₂) production via the two-electron oxygen reduction reaction (2e^- ORR) offers a sustainable and on-site generation strategy.
• Developing efficient catalysts is crucial for advancing environmentally friendly H₂O₂ synthesis.

Purpose of the Study:

• To synthesize and evaluate a bismuth-doped cerium oxide (Bi_0.1Ce_0.9O₂) catalyst for the 2e^- ORR.
• To investigate the effect of Bi doping on the catalytic activity and selectivity for H₂O₂ production.

Main Methods:

• One-step hydrothermal in situ self-assembly method for synthesizing Bi_0.1Ce_0.9O₂.
• Synchrotron radiation X-ray diffraction (SR-XRD) and theoretical calculations to analyze catalyst structure and active sites.
• Electrochemical evaluation of the 2e^- ORR activity, selectivity, yield, and stability.

Main Results:

• Bi doping induced lattice expansion and created dual Ce/Bi active sites in CeO₂.
• Bi incorporation enhanced O₂ adsorption at Ce sites and weakened *OOH adsorption at Bi sites, promoting the 2e^- ORR.
• The Bi_0.1Ce_0.9O₂ catalyst achieved 93.7% H₂O₂ selectivity, a yield of 656 mmol g_cat^-1 h^-1, and 21 h stability.

Conclusions:

• Bismuth-doped cerium oxide is a highly effective catalyst for electrochemical H₂O₂ production.
• The study provides insights into designing efficient rare-earth oxide catalysts for sustainable H₂O₂ synthesis.
• The catalyst's performance in bleaching applications confirms its practical utility.