Cobalt modified platinum-cellulose-carbon aerogel prepared by supercritical deposition as electrocatalyst for hydrogen evolution reaction

Abstract

Green hydrogen production via water electrolysis is a key technology for reaching net-zero CO2 emission targets due to its ability to generate high-purity hydrogen with minimal environmental impact. This study investigates the effect of Co on Pt-based electrocatalysts supported on cellulose-based carbon aerogels (cellulose-CA) using supercritical deposition (SCD) on hydrogen evolution reaction (HER) activity and stability. Pt and Co precursors were deposited onto cellulose-CA via SCD and converted via two routes (ex-situ thermal and chemical) under N-2 and H-2 flow at 1 bar and 200 degrees C. Characterizations (ICP-MS, STEM, XPS, SEM, Raman, and XRD) confirmed successful Pt and Co incorporation and preservation of the cellulose-CA microstructure (overall accessible surface area similar to 2100 - 2700 m(2) g(-1)). The Co-modified electrocatalysts exhibited similar overpotentials at 20 mA/cm(2) despite half the Pt loading, with thermally converted Pt-Co-cellulose-CA showing the lowest overpotential (64 mV) and potential shift (4 mV). Our results demonstrate that Co-modification via SCD enhances the activity and stability of biobased CA electrocatalysts with low Pt content around 2.8 wt%.