Porous Silicon-Based Catalysts for the Dehydration of Glycerol to High Value-Added Products.

Increasing worldwide biodiesel production has led to the generation of an important glycerol surplus, which needs to be valorized in order to improve the economic and environmental sustainability of the biodiesel industry. In this context, glycerol dehydration to acrolein by acid catalysis appears to be a potential route of glycerol valorization, since acrolein is an important intermediate for many chemical industries. The main drawback of this catalytic process is catalyst deactivation. Different alternatives have been proposed for overcoming it, such as the use of mesoporous materials in order to facilitate the diffusion of glycerol and reaction products, thus minimizing deactivation. This review compiles the main achievements of the use of mesoporous silica-containing materials that have been deployed either as a catalyst or for support in glycerol dehydration to acrolein. Thus, the effect of mesoporosity on both catalytic performance and deactivation will be discussed, as well as the blocking of pores by coke deposition.