1成果簡(jiǎn)介

　　氧還原反應(yīng)（ORR）是鋅空氣電池等可再生能源技術(shù)的基石，但其緩慢的動(dòng)力學(xué)特性及對(duì)貴金屬催化劑的依賴仍是關(guān)鍵瓶頸。本文，中國(guó)科學(xué)院福建物質(zhì)結(jié)構(gòu)研究所韓麗麗 研究員、溫州大學(xué)錢金杰 副教授、天津大學(xué)劉輝 英才教授等在《ADVANCED MATERALS》期刊發(fā)表名為“Covalent Dangling of
Poly-Indium-Phthalocyanine Over Carbon Nanopits as Superior Oxygen Reduction Catalyst for Flexible Zn-Air Battery”的論文，研究報(bào)道了一種創(chuàng)新催化劑——通過(guò)將聚銦酞菁共價(jià)懸掛于碳納米管缺陷區(qū)構(gòu)建的碳納米管（InPPc/v-CNTs）。

　　該結(jié)構(gòu)誘導(dǎo)軸向In-C配位，打破平面In-N4中心的對(duì)稱電子分布，強(qiáng)化了電子金屬-載體間相互作用。理論計(jì)算表明，這種扭曲的電子環(huán)境既增強(qiáng)了O2吸附/解離動(dòng)力學(xué)，又降低了*OH脫附能壘，從而協(xié)同提升了ORR動(dòng)力學(xué)。得益于定制電子結(jié)構(gòu)與優(yōu)化的金屬-載體配置，InPPc/v-CNTs展現(xiàn)出卓越的氧還原反應(yīng)活性與穩(wěn)定性：半波電位達(dá)0.90V vs RHE，動(dòng)力學(xué)電流密度達(dá)42.9mA cm?2（遠(yuǎn)超Pt/C基準(zhǔn)值10倍以上）。此外，在水系鋅空氣電池中，該材料展現(xiàn)出270 mW cm?2的卓越功率密度，并在5 mA cm?2電流密度下保持高達(dá)865小時(shí)的放電穩(wěn)定性。本研究通過(guò)將缺陷工程、電子不對(duì)稱性與大分子穩(wěn)定化技術(shù)融合為統(tǒng)一框架，突破了傳統(tǒng)催化劑設(shè)計(jì)局限，為金屬酞菁類氧還原反應(yīng)催化劑開創(chuàng)了全新范式。

2圖文導(dǎo)讀

圖1.a) Schematic synthesis of InPPc/v-CNTs. b) HRTEM images of CNTs and v-CNTs. c) TEM and d) HRTEM images of InPPc/v-CNTs. e,f) AC-HAADF-STEM images of InPPc/v-CNTs, the isolated In sites are highlighted by yellow circles, and inset in f) is the 3D atom-overlapping Gaussian-function fitting map of the isolated In site marked with a pink circle. g) HAADF image and elemental mappings of InPPc/v-CNTs.

圖2、(a) XRD patterns of InPPc, CNTs, v-CNTs, and InPPc/v-CNTs. (b) Raman spectra of CNTs, v-CNTs, and InPPc/v-CNTs. High-resolution (c) C 1s, (d) N 1s, and (e) In 3d XPS of InPPc, InPPc/CNTs, and InPPc/v-CNTs. (f) XANES, (g) Fourier-transformed EXAFS and (h) WT-EXAFS spectra of InPPc, InPPc/CNTs, InPPc/v-CNTs, and In foil at the In K-edge.

圖3、a) LSVs and b) Tafel plots of InPPC/v-CNTs, InPPc/CNTs, InPPc, v-CNTs, CNTs, and Pt/C at 1600 rpm in O2-saturated 0.1 M KOH electrolyte. c) Comparison of E1/2 and Tafel slopes between InPPc/v-CNTs and recently reported ORR catalysts. d) LSV polarization curves at different rotation speeds and corresponding K?L plots of InPPc/v-CNTs. e) Comparison of Jk and MA at 0.85 V among InPPC/v-CNTs, InPPc/CNTs, and Pt/C. f) Chronoamperometric curves and LSVs of InPPc/v-CNTs initially and after 5, 10, and 15k ADT CV cycles.

圖4、a) Schematic of the home-made aqueous rechargeable ZAB. b) OCV plots, c) discharge polarization and power density curves, d) specific discharge capacities at 10 mA cm2, and e) galvanostatic discharge curves at various current densities of the aqueous ZABs with InPPc/v-CNTs and Pt/C+RuO2 as cathodes, respectively. f) Application demonstration of charging a smartphone using the aqueous ZAB with the InPPc/v-CNTs cathode. g) Discharge–charge cycling at 5 mA cm?2 of the aqueous ZABs with InPPc/v-CNTs and Pt/C+RuO2 as cathodes, respectively. (h) OCV plots and i) discharge–charge cycling at 5 mA cm?2 of the quasi-solid-state rechargeable ZABs, insets show photographs of the quasi-solid-state ZABs in various states: flat (0°), bent (45°), bent (90°), bent (180°), and returned to flat (0°).

圖5、a) Adsorption configurations of *OOH, *O, and *OH intermediates on the InPPc/v-CNTs catalyst model. b) Projected DOS (PDOS) of the In–N4 center in different models. (c) Structural models with differential charge densities upon adsorption of O2 (yellow and cyan isosurfaces represent the electron accumulation and depletion, respectively). d) O2 adsorption energy and Bader charge analysis for InPPc/v-CNTs, InPPc/CNTs, and InPPc. e) ORR Gibbs free energy diagrams at 1.23 V for InPPc/v-CNTs, InPPc/CNTs, and InPPc. f) ORR Gibbs free energy diagrams at 1.23, 0.76, and 0 V for InPPc/v-CNTs.

3小結(jié)

　　綜上所述，我們通過(guò)將聚銦酞菁（InPPc）共價(jià)錨定于納米坑缺陷工程化碳納米管（v-CNTs）上，實(shí)現(xiàn)了氧還原催化領(lǐng)域的突破性進(jìn)展。通過(guò)碳納米坑處的共價(jià)鍵合形成的軸向In–C配位，打破了平面In–N4中心的對(duì)稱電子分布，同時(shí)促進(jìn)了強(qiáng)健的電子金屬-載體相互作用。密度泛函理論揭示，這種電子不對(duì)稱性優(yōu)化了O2吸附/解離動(dòng)力學(xué)，并降低了*OH中間體脫附的能量障礙，從而協(xié)同加速了四電子氧還原反應(yīng)路徑。該InPPc/v-CNTs催化劑展現(xiàn)卓越性能：半波電位達(dá)0.90 V，動(dòng)力學(xué)電流密度達(dá)42.9 mA cm?2（遠(yuǎn)超基準(zhǔn)Pt/C的10倍以上），并在30小時(shí)內(nèi)保持優(yōu)異穩(wěn)定性。在液態(tài)鋅空氣電池中，該催化劑峰值功率密度達(dá)270 mW cm?2，并能穩(wěn)定放電865小時(shí)，性能超越多數(shù)酞菁類及非貴金屬氧還原反應(yīng)催化劑。此外，在準(zhǔn)固態(tài)鋅空氣電池中，該材料展現(xiàn)出1.5伏的高開路電壓、92.0mW cm?2的峰值功率密度，以及優(yōu)異的可重復(fù)充電性和可折疊性。通過(guò)整合缺陷工程、電子不對(duì)稱調(diào)制與高分子穩(wěn)定化技術(shù)，本研究為鄰苯二甲酰亞胺類分子電催化劑在下一代可持續(xù)能源系統(tǒng)中的未來(lái)研究方向提供了新思路。

　　文獻(xiàn)
:https://doi.org/10.1002/adma.202522225

來(lái)源：材料分析與應(yīng)用