Fluoranthene-based metal-free hyper-crosslinked polymers for NaBH4 methanolysis: mechanistic role of surface-charge effects

Gokkus K., ÖZBAL A., Gür M., AKALIN S. A., Senturan U. M., BÜTÜN V.

Fuel, vol.421, 2026 (SCI-Expanded, Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 421
  • Publication Date: 2026
  • Doi Number: 10.1016/j.fuel.2026.139061
  • Journal Name: Fuel
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC
  • Keywords: Friedel–Crafts alkylation, Hydrogen generation, Hyper-crosslinked polymers, Metal-free catalysis, NaBH4 methanolysis, Surface area
  • Eskisehir Osmangazi University Affiliated: Yes

Abstract

Fluoranthene-based hyper-crosslinked polymers (HCPs) were synthesized via Friedel–Crafts alkylation and evaluated as metal-free catalysts for hydrogen generation through NaBH4 methanolysis. Despite moderate hydrogen-generation rates relative to some polymeric systems, the catalysts exhibited distinct structure–activity behavior that could not be explained by surface area or heteroatom content alone. Notably, HCP-4 achieved the highest hydrogen-generation rate (31,200 mL H2 min−1 gcat−1 at 333.15 K), whereas HCP-1 showed the lowest apparent activation energy (23.6 kJ mol−1), indicating decoupled kinetic and textural contributions. Zeta-potential analysis revealed pronounced reaction-induced modulation of surface charge, identifying interfacial electrostatics as a dominant mechanistic factor governing hydride activation. These findings demonstrate that π-conjugated polymer architecture and surface-charge regulation, rather than conventional structural descriptors, control catalytic behavior in metal-free NaBH4 methanolysis.