H₂S in Black Sea: Turning an environmental threat to an opportunity for clean H₂ production via an Electrochemical Membrane Reactor. Research progress in H₂S-PROTON Project

¹ Chemical Process & Energy Resources Institute (C.P.E.R.I.), Centre for Research and Technology Hellas (CE.R.T.H.), P.O. Box 60361, 57001, Thermi-Thessaloniki, Greece
² Department of Mechanical Engineering, University of Western Macedonia, Bakola & Sialvera, 50100, Kozani, Greece
³ Technical University of Crete, School of Production Engineering and Management, Chania, 73100, Crete, Greece

^a Corresponding author: gmarnellos@uowm.gr

Abstract

The present study aims to examine and evaluate the concept of H₂S decomposition to H₂ production in (H²)-conducting electrochemical reactors. In such a complex process, one of the major issues raised is the optimal selection of materials for the electrochemical cell. Specifically, the anode electrode should exhibit high catalytic activity and electronic conductivity, in order to make the process efficient. In this context, and before the electrochemical tests, a number of transition metal catalysts supported on CeO₂ were prepared using the wet impregnation method and tested for their performance regarding the activity/stability of the H₂S decomposition reaction, in the absence and presence of H₂O. The experimental results are accompanied by the corresponding thermodynamic calculations, at various reaction conditions. The physico-chemical characteristics of the employed catalysts were determined using the BET, XRD, SEM and elemental analysis methods. The experimental results showed that the catalysts 20% wt. Co/CeO₂ and 30% wt. Co/CeO₂ exhibit high H₂S conversions, in the absence and presence of H₂O respectively, comparable to conversions indicated by thermodynamics and with remarkable stability, which is attributed to the in-situ sulfation of catalysts’ active components during their exposure at the feedstock mixture.