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Article Citation - WoS: 15Citation - Scopus: 17Pei Modifiednatural Sands of Florida as Catalysts for Hydrogen Production From Sodium Borohydride Dehydrogenation in Methanol(Wiley-hindawi, 2021) Inger, Erk; Demirci, Sahin; Can, Mehmet; Sunol, Aydin K.; Philippidis, George; Sahiner, NurettinSand samples from Tampa (T) and Panama (P) City beaches in Florida were used as catalysts for dehydrogenation of NaBH4 in methanol. T and P sand samples were sieved to <250, 250 to 500, and >500 mu m sizes, and the smallest fractions resulted in faster hydrogen generation rates (HGR), 565 +/- 18 and 482 +/- 24 mL H-2 (min.g of catalyst)(-1), respectively. After various base/acid treatments, HGR values of 705 +/- 51 and 690 +/- 47 mL H-2 (min g of catalyst)(-1) for HCl-treated T and P sand samples were attained, respectively. Next, T and P sand samples were modified with polyethyleneimine (PEI) that doubled the HGR values, 1344 +/- 103, and 1190 +/- 87 mL H-2 (min.g of catalyst)(-1) and increased similar to 8-fold, 4408 +/- 187, and 3879 +/- 169 mL H-2 (min g of catalyst)(-1), correspondingly after protonation (PEI+). The Ea values of T and P sand samples were calculated as 24.6 and 25.9 kJ/mol, and increased to 36.1, and 36.6 kJ/mol for T-PEI(+)and P-PEI(+)samples, respectively.Article Citation - WoS: 51Citation - Scopus: 52Porous Carbon Particles as Metal-Free Superior Catalyst for Hydrogen Release From Methanolysis of Sodium Borohydride(Pergamon-elsevier Science Ltd, 2020) Demirci, Sahin; Yildiz, Mustafa; Inger, Erk; Sahiner, NurettinCarbon materials can be readily prepared from wood derivatives, monosaccharaides such as pentose/hexose and/or polysaccharides in addition to many starting materials by treatment of thermal, chemical and hydrothermal methods. Here, the porous carbon (PC) particles were prepared by removal of silica particles from previously prepared carbon-silica composites by hydrothermal and carbonization process from sucrose. Then, PC particles were modified with polyethyleneimine (PEI) to prepared amine functionalized PC-PEI particles and protonated with hydrochloric acid, PC-PEI+. Finally, these prepared carbon-based particles were used as catalyst for H-2 release from NaBH4 methanolysis and PC-PEI+ was found as the most effective catalyst at 25 degrees C with 4040 +/- 126 mL H-2. min(-1).g(-1) HGR value. The E s value of 23.9 kJ/mol in H-2 release reaction from NaBH4 methanolysis catalyzed by PC-PEI+ that is comparable and/or better than most of studies reported in literature. The activity% of PC-PEI+ catalyst was 72% after fifth consequential runs. Additionally, the regeneration ability of PC-PEI+ catalyst was also shown that after fifth regeneration process, there is only 5% decrease in activity%. (C) 2019 Elsevier Ltd. All rights reserved.
