The environmental benefits of biodiesel produced from fully renewable resources should not be underestimated; its production follows the principles of green chemistry and it closes the carbon cycle. Nevertheless, high production costs preclude the replacement of petroleum-based diesel fuel with biodiesel. The introduction of a solid heterogeneous catalyst in biodiesel production contributed to reducing the biodiesel price, thus moving toward competitiveness with diesel. Lin's group was at the forefront of this endeavor and invented and developed one of the first heterogeneous catalysts for generating biodiesel. Nowadays, current catalysts catalyze transesterification and esterification at low temperatures, are stable, especially in water, and have high selectivities.