Catalytic conversions of isocyanate to urea and glucose to levulinate esters over mesoporous alpha-Ti(HPO4)(2)center dot H2O in green media

摘要

We have described a facile solvothermal synthesis of a sheet-like alpha-Ti(HPO4)(2)center dot H2O nanomaterial. The material comprises 10.7 nm nanoparticles along with ordered mesopores throughout its hexagonal building blocks. The material possesses a bandgap of 3.86 eV and works as an efficient catalyst for the selective synthesis of ureas from a broad range of isocyanates in the presence of H2O at room temperature with a high product yield (up to 93%) and a TOF value up to 15.25 h(-1). The alpha-Ti(HPO4)(2)center dot H2O nanomaterial also catalytically converts glucose to levulinic acid (LA) and subsequently LA to alkyl levulinates in the presence of different alcohols with a high product yield (up to 98%) and a TOF value up to 43.00 h(-1). Furthermore, all the reactions are performed under green and facile catalytic conditions without using any hazardous solvent. The alpha-Ti(HPO4)(2)center dot H2O catalyst material was also found to be reusable for manifold cycles for all the reactions, keeping its catalytic efficiency along with its structural and morphological characteristics unaffected, supporting its industrial relevance.