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Surface‐modified carbon black derived from used car tires as alternative, reusable, and regenerable catalysts for H 2 release studies from sodium borohydride methanolysis
Author(s) -
Ari Betul,
Ay Mehmet,
Sunol Aydin K.,
Sahiner Nurettin
Publication year - 2019
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.4742
Subject(s) - catalysis , sodium borohydride , chemistry , carbon black , epichlorohydrin , nuclear chemistry , sulfuric acid , organic chemistry , natural rubber
Summary Carbon black (CB) obtained from used car tire rubbers were treated with concentrated sulfuric and nitric acids. The oxidized CB (CB‐COO‐Na + ) is subsequently modified with epichlorohydrin (ECH) and amines including polyethylene imine (PEI). These modified CBs such as CB‐PEI are used as metal‐free catalysts in methanolysis of sodium borohydride (NaBH 4 ) to produce hydrogen. The hydrogen generation rate (HGR) of 3089 ± 44.69 mL.min ‐1 .g ‐1 is accomplished at room temperature with CB‐PEI‐hydrochloric acid (HCl) catalyst. The resulting activation energy of 34.7 kJ/mol for the temperature range of −20°C to +30°C compares favorably to most of alternative catalysts reported in literature while reaction catalyzing capabilities of CB‐PEI‐HCl particles extend to the subzero temperature range (−20°C‐0°C). The reuse and regeneration studies conducted for the CB‐PEI‐HCl catalyst showed that these catalysts do provide complete conversion at every use up to five consecutive runs and retain 50 ± 2.5% of the original hydrogen generation rate at the fifth consecutive reuse. The CBs‐based catalysts are fully regenerated with HCl treatment.