Synergistic effect of Pd-Co3O4 nanoparticles supported on coffee-derived sulfur, nitrogen-codoped hierarchical porous carbon for efficient methanolysis of NaBH4

Sulfur, nitrogen-codoped (SN-doped) highly porous carbon nanostructures (CNSs) are established as effi-cient components for hydrogen generation applications. Waste coffee grounds are carbonized in situ and activated with KOH to produce hierarchically SN doped porous carbon nanostructures with a large specific surface area of 2320 m2 g-1. The amorphous and highly active Pd-Co3O4 nanoparticles (NPs) are anchored onto an SN-codoped carbon nanosheet prepared via a simple hydrothermal reaction. An effective method for optimization of the Pd-Co3O4/SN-CNS-60 0 catalytic efficiency for NaBH4 methanolysis using sodium sulfide as a precursor or combination of sulfur-containing salts as a raw material is proposed. The Pd-Co3O4/ SN-CNS-60 0 catalyst exhibits an excellent catalytic activity for NaBH4 catalytic methanolysis at room temperature, with a high hydrogen generation rate of 20158 mL H2 min-1 gcat-1. The methanolysis reaction activation energy in an aqueous NaBH4 solution is approximately 14.52 kJ/mol. The excellent Pd-Co3O4/SN-CNS-60 0 catalytic activity is attributed to the small size and amorphous state of Pd-Co3O4 NPs, good sy-nergistic interaction between Pd-Co3O4 NPs and SN-CNS with a large specific surface area, and abundant defects. Highly efficient, inexpensive, and environment-friendly catalysts are successfully developed for hydrogen generation.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Sulfur, nitrogen-codoped highly porous carbon nanostructures are used as efficient components for hydrogen generation. The waste coffee grounds are carbonized and activated to produce hierarchically SN doped porous carbon nanostructures. Pd-Co3O4 nanoparticles are anchored onto SN-codoped carbon nanosheets. An effective method for optimization of the Pd-Co3O4/SN-CNS-600 catalytic efficiency is proposed. The catalyst exhibits excellent catalytic activity for NaBH4 catalytic methanolysis at room temperature with a high hydrogen generation rate.