Abstract: The synthesis of dimethyl carbonate (DMC) from CO2 represents a crucial application in C1 chemical conversion, where the alcoholysis of ethylene carbonate (EC) serves as the key step in this route. Although industrial sodium methoxide catalysts exhibit high activity, their strong alkalinity imposes stringent equipment requirements and generates environmental burdens due to non-recyclability and product separation challenges. Bimetal oxide catalysts have emerged as ideal heterogeneous catalytic materials for alcoholysis reactions owing to their tunable Lewis acid-base dual active sites and structural designability. However, current research faces critical scientific issues such as difficulty in synergistic optimization of catalytic activity and stability, unclear structure-activity regulation mechanisms, cumbersome preparation routes, harsh reaction conditions, and insufficient investigation on intensified synthesis strategies for bimetal oxide catalysts, which collectively hinder the design of heterogeneous catalytic systems for DMC synthesis. This study innovatively proposed an ultrasonic hydrothermal-ionic liquid-mediated regulation strategy. By employing the ultrasonic hydrothermal method combined with the ionic liquid [Bmim]BF4 as a structure-directing agent, a Mg-Zr bimetallic oxide catalyst (UIL-MgZrO) with both excellent activity and stability was successfully constructed. The influence mechanisms of the coupling between ionic liquid-mediated processes and different intensified preparation methods on the crystal growth, phase evolution, and surface characteristics of catalysts were systematically investigated, where the gradual transformation of crystals into a stable monoclinic phase with prolonged ultrasonic duration was observed. The operational principles for synergistic regulation of active sites in metal oxides were revealed, thereby improving the catalytic efficiency of bimetallic oxides. In alcoholysis reactions, the UIL-MgZrO catalyst achieved 72.1% EC conversion with 99.9% DMC selectivity under mild conditions (90℃, 1 h), representing top-tier performance among reported heterogeneous catalytic systems. This work provides new strategies for precise regulation of metal oxide surface properties and technical support for CO2-based carbonate synthesis processes, and offers potential applications for energy-related chemical production.

Key words: ionic liquids-modulated, ultrasonic hydrothermal synthesis, metal oxides, dimethyl carbonate, alcoholysis

摘要： 利用CO2合成碳酸二甲酯(DMC)是C1化学转化的重要应用，其中碳酸乙烯酯(EC)醇解反应制备DMC是该路线的关键步骤。工业催化剂甲醇钠具有高催化活性，但其过强的碱性对设备提出了严格要求，且使用后无法回收利用，增加产品分离难度的同时造成了环境负担。双金属氧化物催化剂凭借其可调控的Lewis酸碱双活性位点及结构可设计性等优势，被视为醇解反应的理想非均相催化材料。然而，现有研究仍面临催化剂活性与稳定性难以协同优化、催化剂构效调控规律不清晰、制备路线繁冗和催化条件苛刻等关键科学问题，且针对该反应的双金属氧化物催化剂的强化合成策略也尚缺少深入研究，制约了非均相催化体系的设计及在DMC合成中的应用。因此，本研究创新性地提出了超声水热-离子液体介导法调控策略，以[Bmim]BF4离子液体为导向模板剂，通过超声辅助水热法成功构建了活性和稳定性俱佳的Mg-Zr双金属氧化物催化剂(UIL-MgZrO)，系统研究了离子液体介导与不同强化制备手段的耦合作用对催化剂晶体生长、晶相演变及表面特性的影响机制，揭示了协同调控金属氧化物活性位点的作用规律，从而改善双金属氧化物的催化效率。在醇解过程中，所制备的UIL-MgZrO催化剂在温和条件(90℃，1 h)下实现了72.1%的EC转化率和99.9%的DMC选择性，其性能指标处于目前已报道的非均相体系醇解的较高水平。本研究为金属氧化物表面结构性质的精确调控提供了新策略，为CO2合成碳酸酯工艺提供了技术支持。

关键词: 离子液体介导, 超声水热合成, 金属氧化物, 碳酸二甲酯, 醇解