Natural Celluloses as Catalysts in Dehydrogenation of NaBH(4) in Methanol for H(2) Production

[Image: see text] Cellulose, the most abundant renewable biopolymer, exists in many forms, such as microgranular cellulose (MGCell), sigmacell cellulose (SCell), cellulose fibers (FCell), and α-cellulose (AlfaCell). Several of these cellulose forms were protonated with an amine-containing agent polyethyleneimine (PEI), and the modified celluloses (XCell-PEI(+)) were studied as catalysts in methanolysis of NaBH(4) for hydrogen (H(2)) generation. It was found that the SCell-PEI(+)-catalyzed reaction is the fastest one among the modified celluloses with a hydrogen generation rate of 5520 ± 119 mL H(2)/(g of catalyst × min). The activation energies of MGCell-PEI(+), SCell-PEI(+), FCell-PEI(+), and AlfaCell-PEI(+) were determined as +21.7, +23.4, +24.8, and + 21.8 kJ/mol, respectively. Reusability of catalysts was investigated, and regeneration of cellulose based catalysts after the fifth cycle could be readily achieved by HCl treatment to completely recover its activity. Therefore, PEI-modified-protonated cellulose forms constitute sustainable, re-generable, and renewable catalysts for production of H(2), an environmentally benign green energy carrier.