writer：Hao Zhang, Siyang Yu, Shixiong Cao, Xiaobo Liu, Jun Tang, Lingyu Zhu, Jianbing Ji, and Jianli Wang
keywords：pickering emulsion, pickering interfacial catalysts
source：期刊
specific source：ACS Omega
Issue time：2021年

Pickering乳液体系为在静态条件下同时强化和催化甘油三酯与甲醇的酯交换提供了潜在的平台。然而，由于乳化液在反应温度下的稳定性较低，实现具有高生物柴油收率的静态酯交换仍然具有挑战性。本文构建了一系列表面亲和性相似但密度不同的磁性可回收皮克林界面催化剂(PICs)作为大豆油/甲醇乳液的稳定剂。从液滴沉降和催化剂颗粒脱落的角度，对乳化液体积分数和液滴尺寸的变化进行了对比研究和分析。研究发现，除了表面亲和力外，由于重力对催化剂在甘油三酯/甲醇乳液中的吸附有不可忽视的影响(特别是在高温下)，PIC密度对乳液的稳定性也起着关键作用。通过降低密度，精细改善亲油性，优化PIC的加入量，得到的大豆油/甲醇乳液在60℃下能保持稳定至少12 h，实现静态酯交换，生物柴油收率高达95.6%。此外，性能最好的PIC可以重复使用至少7个周期。这种高效的静态酯交换系统为生物柴油生产提供了一种绿色策略。

Pickering emulsion systems provide potential platforms for simultaneously intensifying and catalyzing transesterification between triglyceride and methanol under static conditions. However, realizing static transesterification with high biodiesel yield is still challenging due to low emulsion stability at the reaction temperature. Here, a series of magnetically recyclable Pickering interfacial catalysts (PICs) with similar surface affinities but diferent densities were constructed as stabilizers of a soybean oil/methanol emulsion. The variations in the emulsion volume fraction and viewpoint of droplet settling and catalyst particle shedding. It is found that, expect for surface affinity, PIC density also plays a pivotal role in emulsion stability owing to the non-negligible effect of gravity on catalyst adsorption in triglyceride/methanol emulsion (especially at elevated temperature ). By reducing the density, finely improving the lipophilicity, and optimizing the addition amount of PIC, the obtained soybean oil/methanol emulsion can remain stable for at least 12h at 60℃, enabling static transesterification with a high biodiesel yield of 95.6%. Moreover, the best performing PIC can be reused for at least 7 cycles. This efficient static transesterification system offers a green strategy for biodiesel production.

DOI: 10.1021/acsomega.1c00629

浙江省自然科学基金项目(LY18B040004)和中国博士后科学基金项目(2020M671790)资助。