NaCl Microporogen-Assisted Hollow Microporous Organic Polymers Bearing Zn-Salphens for Enhanced Biomass Conversion to Biodiesel

Hollow microporous organic polymers bearing Zn-salphen species (HMOP-Zn) were engineered via template synthesis using micrometer-sized NaCl crystals as porogens. The NaCl porogens could be easily etched from NaCl@MOP-Zn by simple water washing without causing Zn etching from HMOP-Zn. HMOP-Zn was utilized as a heterogeneous Lewis acid catalyst for the transesterification of soybean oil with methanol to produce biodiesel. Due to the hollow morphology effect, HMOP-Zn exhibited superior catalytic performance compared to a control nonhollow MOP-Zn catalyst. In addition, HMOP-Zn could be recycled while maintaining its original catalytic activity for five successive reactions.