Untangling the cobalt promotion role for ruthenium in sodium borohydride dehydrogenation with multiwalled carbon nanotube‐supported binary ruthenium cobalt catalyst
Tülin Avcı Hansu, Ömer Şahi̇n, Aykut Çağlar, Hilal Kıvrak
Abstract
Summary In the present study, multiwalled carbon nanotube‐supported Ru (Ru/MWCNT) and RuCo (RuCo/MWCNT) nanocatalysts with 3 wt% Ru loading were synthesized via sodium borohydride (SBH) reduction method for the dehydrogenation of SBH (R SBH ) . These nanocatalysts were characterized with XRD, XPS, SEM–EDX, and TEM. Ru/MWCNT and Ru:Co/MWCNT catalysts with varying Ru:Co atomic ratios were prepared successfully, and electronic state of Ru:Co altered compared to Ru. R SBH activities of these Ru/MWCNT and RuCo/MWCNT were examined in alkaline environment. RuCo/MWCNT at 80:20 atomic ratio exhibits superior H 2 evolution. Further experiments were performed with RuCo/MWCNT at 80:20 atomic ratio to determine how NaOH concentration (C NaOH ), reaction temperature (T rxn ), SBH concentration (C SBH ), and amount of nanocatalyst (M c ) affect R SBH activities. Activation energy (Ea) was calculated using the Arrhenius equation. RuCo/MWCNT at 80:20 atomic ratio exhibits superior H 2 evolution activities compared to the literature values. Initial rate (IR) for this nanocatalyst was found as 123.9385 mL H 2 g −1 cat min −1 . As a result of these kinetic calculations, the Ea of the nanocatalysts was calculated as 35.978 kJ/mol. The degree of reaction (n) was found to be 0.53 by trial and error. RuCo/MWCNT at 80:20 atomic ratio is a promising nanocatalyst for R SBH .