Copper Nanowires as Highly Efficient and Recyclable Catalyst for Rapid Hydrogen Generation from Hydrolysis of Sodium Borohydride

Abstract

Hydrogen (H2) is a clean energy carrier which can help to solve environmental issues with the depletion of fossil fuels. Sodium borohydride (NaBH4) is a promising candidate material for solid state hydrogen storage due to its huge hydrogen storage capacity and nontoxicity. However, the hydrolysis of NaBH4 usually requires expensive noble metal catalysts for a high H2 generation rate (HGR). Here, we synthesized high-aspect ratio copper nanowires (CuNWs) using a hydrothermal method and used them as the catalyst for the hydrolysis of NaBH4 to produce H2. The catalytic H2 generation demonstrated that 0.1 ng of CuNWs could achieve the highest volume of H2 gas in 240 min. The as-prepared CuNWs exhibited remarkable catalytic performance: the HGR of this study (2.7 × 1010 mL min−1 g−1) is ~3.27 × 107 times higher than a previous study on a Cu-based catalyst. Furthermore, a low activation energy (Ea) of 42.48 kJ mol−1 was calculated. Next, the retreated CuNWs showed an outstanding and stable performance for five consecutive cycles. Moreover, consistent catalytic activity was observed when the same CuNWs strip was used for four consecutive weeks. Based on the results obtained, we have shown that CuNWs can be a plausible candidate for the replacement of a costly catalyst for H2 generation.

Catalytic dechlorination of 1,2-DCA in nano Cu0-borohydride system: effects of Cu0/Cun+ ratio, surface poisoning, and regeneration of Cu0 sites

“…With Cu 0 and borohydride, Raut et al 10 also did not observe any effect on chlorobenzene (> 90%) dechlorination at the highly alkaline pH of 10–12. With copper nanowire as a catalyst at 298 K, Hashimi et al 83 also did not observe any effect of pH increase from 10.45 to 12 on the H 2 generation but it completely stopped at pH 13. …”

“…The hydrolysis of NaBH 4 and consequently the H 2 generation can be significantly influenced by pH 81 , 83 . As no buffer was used to control the pH in our experiments to avoid any complexity, the initial pH ranged between 9.18 and 9.93 which increased to > 10.5 (10.5–10.8) at the end of the experiments (SI Table S4).…”

“…17 ), which comes from NaBH 4 hydrolysis (Eq. 3 ) 83 . Alkaline conditions precipitate out NaBO 2 , resulting in the blockage of reactive sites which would hinder the H 2 generation 84 and consequently the contaminant removal.…”

Recent Advancement of Emerging Nano Copper-Based Printable Flexible Hybrid Electronics

“…In order to obtain high aspect ratio Cu nanowires, it is important to control the synthesis parameters of nanowires to increase the nucleation and crystal growth rate. The synthesis of Cu nanowires requires a copper precursor source, such as Cu­(NO 3 ) 2 , or Cu­(Cl) 2 , a reducing agent, such as hydrazine, ascorbic acid, glucose, or dextrose, and a capping ligand to control one-dimensional growth, such as ethylenediamine (EDA), − hexadecylamine (HDA), − sodium dodecyl benzenesulfonate (SDBS), polyvinylpyrrolidone (PVP), − cetyltrimethylammonium bromide (CTAB), or octadecylamine (ODA). − The concentrations of reducing agent and capping ligands play an important role in the formation of Cu nanowires, and the heating temperature and reaction time also have a significant influence on the diameter and length of Cu nanowires. Figure a–c shows the reduction of copper ions into the synthesis of copper nanowires with the extension of heating time using the royal blue precursor solution containing Cu­(NO 3 ) 2 , EDA, hydrazine, and sodium hydroxide.…”

Hydrogen-free hydrogenation of nitrobenzene via direct coupling with cyclohexanol dehydrogenation over ordered mesoporous MgO/SBA-15 supported Cu nanoparticles

“…8 The global increasing demand for hydrogen energy makes researchers to develop remarkably efficient and innovative catalytic process to produce chemical feed stocks. 9 Catalytic transfer hydrogenation (CTH) of nitro compounds using hydrazine, NaBH 4 , and HCOOH as H 2 donors offers an alternative approach for the hydrogenation NB using molecular H 2 . 10 However, the application is hampered due to the separation steps required for the catalyst reuse.…”