Preparation And Catalytic Performance Of Alginate Based Aerogel Functional Materials

Sodium alginate?SA?is a naturally rich polysaccharide widely found in algae and soil bacteria.Although alginate can be obtained from both algae and bacteria,most of the alginate available from algae commercially.There are plenty of brown algae in the ocean,which can regenerate in a short time,providing abundant raw materials for industrial production.Global industrial alginate production is about 30,000 tons a year.Alginate is widely used in food,medicine and textile industry because of its good water retention ability,cementing,viscosification and stability.Because alginate has a number of free hydroxyl and carboxyl groups distributed along the backbone,it is an ideal candidate for chemical functionalization,and has good adsorption capacity for metals cations.As well,alginate can be shaped as self-standing beads,films or monoliths with good mechanical stability.Thus,the alginate became a desirable metal catalyst carrier and had been utilized in some catalytic reactions.In recent years,alginate biomass materials have also been applied in the field of industrial catalysis.Biomass nanocomposite aerogels are one of the attractive emerging materials in the fields of materials chemistry and catalyst industry,but their unsatisfied catalytic performance and mechanical performance has limited their wide applications.In this work,alginate-based nanocomposite aerogels with perfect mechanical strength and great catalytic performance were prepared through incorporating SiO₂ and GO via a simple one-pot reaction.After covalent cross-linking with SiO₂ and GO,the particle compressive strength of the aerogel reached to 31.2 kg/cm² with the perfect conversion of phenol of 82.1%in phenol hydroxylation reaction.Moreover,the aerogel catalysts retained good catalytic stability after five times catalytic reaction.In addition,the rGO-alginate based aerogel catalysts were prepared.The particle strength of the aerogel could reach 42.9 kg/cm²,which was better than that of the GO-alginate based aerogel.The conversion of phenol was 77.4% under rGO-alginate aerogel as catalyst.This alginate-based aerogel provides a novel and environmentally friendly catalyst with high-performance for next generation catalytic industry.