Untangling the cobalt promotion role for ruthenium in sodium borohydride dehydrogenation with multiwalled carbon nanotube‐supported binary ruthenium cobalt catalyst

Abstract

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 .

CuMOF@Faujasite nanocomposite as a novel catalyst for hydrogen production

“…Moreover, upon discussing the reaction order relative to NaBH 4 , the reaction order of n values was found to be first-order kinetics using the trial and error method. [66][67][68] This result can be verified by plotting lnC t vs time for the different catalyst weights, where C t represents the remained concentration of the hydride at different time intervals, the obtained plots are shown in Figure 8b. The slope of the fitted lines of these plots gives the rate constant (K) value whereas the intercept corresponds to "ln a" where "a" is the initial volume of hydrogen produced, the results are shown in Table 3.…”

“…Figure 8a indicates that as the catalyst weight increases, the time needed to end the reaction decreases whereas the hydrogen completion volume increases. Moreover, upon discussing the reaction order relative to NaBH 4 , the reaction order of n values was found to be first‐order kinetics using the trial and error method 66–68 . This result can be verified by plotting lnC t vs time for the different catalyst weights, where C t represents the remained concentration of the hydride at different time intervals, the obtained plots are shown in Figure 8b.…”

Structure of ruthenium nanocatalysts of bismuth, investigation of its effect on hydrolysis performance and kinetic studies

“…NaBH 4 , which contains 10.6% hydrogen in its structure, is a good hydrogen storage 1 . Sodium boron hydride is widely used in the literature due to its hydrogen percentage and easily accessible 2‐6 . By hydrolysis of NaBH 4 at room temperature, only a small percentage of the amount of H 2 expected to be obtained in theory can be obtained.…”

Catalytic Hydrolysis of Sodium Borohydride for Hydrogen Production Using Magnetic Recyclable CoFe2O4-Modified Transition-Metal Nanoparticles

“…Finally, the H 2 generation reactions that were carried out at different temperatures of 298–313 K are given in Figure c. According to the Arrhenius plot of ln k versus 1/ T , the apparent E a was calculated to be approximately 63.11 kJ·mol –1 . − …”