Core-shell catalyst with synergistic hydroxyl and nitrogen active sites for CO₂ cycloaddition

Developing heterogeneous catalyst with multiple active sites has been a hot-spot for cycloaddition of CO₂ with epoxides to value-added chemicals. In this work, a new N- doped carbon/silica core-shell material (M-41/CN) with special hydroxy (Si-OH) and pyridinic N active sites were designed and synthesized. The prepared M-41/CN showed good features: (1) exhibited synergistic effects of Si-OH groups (Acid sites) and pyridinic N species (Lewis basic sites), and (2) held porous structure with specific surface area reaching 308.7 m²/g. The M-41/CN exhibited excellent catalytic activity and stability for cycloaddition of CO₂ with epichlorohydrin, with conversion of epichlorohydrin >98% after 4th reuse. Hence, the M-41/CN with acid-base duality offers a new choice for preparing low-cost, environment-friendly and high-efficiency catalysts for CO₂ conversion.