Restructuring morphology and surface-electronic-structure of Pt-Co3O4-δ-carbon toward ultra-highly efficient hydrogen production. (1st July 2022)

• Record Type: Journal Article
• Authors: Zhu, Hui; Guo, An; Long, Yan; Fan, Guangyin
• Is Part Of: Fuel. Volume 319(2022)
• Publication Date: 2022-07-01
• Subjects: Hierarchically porous structure -- Platinum nanoparticles -- Cobalt oxide -- Hydrogen production -- Ammonium borane; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.123616
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Morphology and surface-electronic-structure reconstruction strategy was developed for hierarchically porous Pt/Co3 O4-δ -UC toward ultrahighly efficient hydrogen evolution from AB hydrolysis with recorded TOFs of 7700 min −1 in aqueous solution and 24, 998 min −1 in basic medium. Highlights: Morphology and surface-electronic-structure reconstruction strategy was developed. The achieved Pt/Co3 O4-δ -UC featured with electron-rich Pt sites and oxygen-vacancy. Pt/Co3 O4-δ -UC with an ultralow Pt loading (0.1 wt%) exhibited excellent performance. Recorded TOFs of 24998 min −1 in basic medium could be obtained for AB hydrolysis. The catalyst has a high durability with 71.3% remained activity after ten cycles. Abstract: Although Pt has been verified as the most active catalyst for hydrogen production, it is highly desirable to minimize the usage of Pt while boost the catalytic performance of catalysts considering the low availability and high price of Pt. Herein, we propose a morphology and surface-electronic-structure reconstruction strategy to realize the anchoring of Pt nanoparticles (NPs) on Co3 O4-δ -carbon matrix via the co-reduction of Pt precursor and Co3 O4 -carbon formed by direct pyrolysis of an aerogel composed of cobalt nitrate, chitosan, and urea. The transformation of the porous-network to hierarchically porous structure consisted of Co3 O4-δ -carbon nanosheets, deposition of electron-rich Pt NPs, and generation of abundant oxygen-vacancy are facilely achieved through flexible co-reduction of Pt(IV) ions and Co3 O4 -carbon with ammonia borane (AB). The achieved Pt/Co3 O4-δ -UC with an ultralow Pt loading (0.1 wt%) exhibits an ultrahigh activity for hydrolytic AB dehydrogenation with turnover frequencies of 7700 min −1 in aqueous solution at 25 ℃. This catalyst also has a high durability with 71.3% remained activity after ten repetitive cycles. The morphology and surface-electronic-structure reconstruction engaged formation of electron-efficient Pt species could accelerate the oxidative cleavage of O − H bond in H2 O and greatly boost the hydrogen generation from hydrolytic AB dehydrogenation. This strategy presented herein offers a new pathway for constructing ultra-highly active supported metal NPs toward hydrogen evolution reaction.