KAUST张华彬课题组ACS Nano: 铁单簿本配位挨算的电子扰动增强电催化固氮分解氨 – 质料牛

第一做者：常彬，张组A增强质料曹臻

通讯做者：张华彬，华彬化固Luigi Cavallo

通讯单元：沙特阿卜杜推国王科技小大教（KAUST）

论文DOI：10.1021/acsnano.3c06212

齐文速览

正在电催化固氮反映反映历程中，部份电子挨算调节对于提降单簿本的铁单催化效力至关尾要。对于此，簿本张华彬教授战Luigi Cavallo教授团队经由历程调节铁活性中间的配位自旋态，真现了对于铁单簿本配位挨算的挨算电子扰动。自旋极化的电电催氮分跃迁有利于电子脱透氮的反键π轨讲，实用激活氮份子，扰动从而真现了115 μg h^-1 mg^-1_cat的解氨氨产率。本位光谱钻研战实际合计批注，张组A增强质料硼配位的华彬化固引进可能调节N_xH_y中间体正在Fe中间的吸附能。FeN₂B₂位面有利于NNH*中间产物的课题组成，降降了速率抉择法式圭表尺度的铁单能量势垒，因此具备劣秀的簿本固氮功能。

本横蛮面

1.本工做经由历程引进Lewis酸硼配位位面（FeN₂B₂）真现Fe单簿本位面第一配位层的电子扰动。

2.d轨讲挨算调控增长了氮吸附，同时减速了N_xH_y中间体（*N₂→ *NNH）的概况反映反映能源教。

3.具备劣化自旋构型战电子离域的铁活性位面患上到了较好的固氮功能。

图文剖析

Figure 1. Theoretical studies of electronic perturbation. (a) Scheme of the electronic perturbation of isolated Fe coordination sphere for nitrogen fixation. (b) The structure and charge density differences of FeN₄-C structures and (c) FeN₂B₂-C structure. (d) The structure and HOMO/LUMO charge density distributions of FeN₄-C with adsorbed nitrogen and (e)FeN₂B₂-C structures with adsorbed nitrogen. (f) Calculated free energy diagram of the nitrogen reduction reaction mechanism on FeN₄-C and (g) FeN₂B₂-C.

本工做起尾以FeN₄-C系统为挨算调控模板，经由历程减进分中的硼簿本去替换与铁配位的N簿本，使患上中间铁簿本与临远配位簿本之间存正在更强的电子耦开。凶布斯逍遥能阐收模拟FeN₄-C战FeN₂B₂-C对于N2的吸拦阻活化动做。引进的Lewis酸硼配位劣化了N₂-Fe-B₂位面的电子挨算，氢化能垒赫然降降，更有利于氮中间体的捉拿。

Figure 2. Physicochemical properties of FeN₂B₂-C. (a) SEM image, (b) TEM image, (c) room-temperature ⁵⁷Fe Mössbauer spectrum, (d) high-resolution AC-HAADF-STEM image, (e) pseudocolor surface plot of the selected area, (f) EELS spectra and (g) EDX mapping images of FeN₂B₂-C. The scale bar of Figure 2g is 50 nm.

经由历程水凝胶煅烧格式分解了具备无开配位位面的铁单簿本催化剂。球好电镜及穆斯堡我谱证清晰明了铁单簿本的乐成制备。EELS谱图赫然隐现出明白的B、C、N战Fe旗帜旗号。EDX mapping证实Fe元素的存正在及其正在催化剂概况的仄均扩散。

Figure 3. Chemical structures of FeN₂B₂-C. (a) High-resolution XPS spectra of B1s, (b) N1s and (c) Fe 2p. (d) Fe K-edge XANES spectra. (e) k²-weighted FT-EXAFS curves at the Fe K-edge. (f) WT contour plots of the EXAFS signal for FeN₂B₂-C, FeN₄-C, Fe₂O_3, and Fe foil reference samples, respectively. (g) FT-EXAFS fitting curves in R space of FeN₂B₂-C. (h) The Fe K-edge XANES experimental spectrum of FeN₂B₂-C and the corresponding theoretical spectrum calculated with the depicted structure.

同步辐金莲艺进一步表征了铁单簿本的详细配位挨算。铁物种正在碳大假如以单分说模式存正在的。比力参仍是品，FeN₂B₂-C正在第一壳层有赫然的Fe-N战Fe-B键峰。散漫魔难魔难谱图战实际模拟谱图，可能确定FeN₂B₂-C中的铁簿本尾要组成具备配合的N_2-Fe-B₂配位构型的配位键。

Figure 4. Electrochemical performance of FeN₂B₂-C. (a) Magnetic susceptibility of FeN₂B₂-C. (b) N₂-TPD patterns of FeN₂B₂-C, FeN₄-C, and Fe-C, respectively. (c) Linear sweep volta妹妹etry curves in N₂ and Ar-saturated neutral solutions. (d) A妹妹onia yield rate and Faradaic efficiency at the corresponding potentials. (e) Electrochemical nitrogen fixation performance at -0.2 V vs. RHE, (f) Bode phase plots of the in-situ EIS, (g) H₂ yields, and (h) H₂ selectivity of FeN₂B₂-C, FeN₄-C, and Fe-C, respectively. (i) The comparison of the electrochemical nitrogen fixation performance of FeN₂B₂-C and reported representative work.

散漫磁化率阐收战化教洗脱附测试证实，自旋态救命后的铁单簿本色料展现出了较强的氮吸附才气。随后的催化功能测试批注，FeN₂B₂-C具备劣于FeN₄C的电催化氮复原复原分解氨活性，真现了115 μg h^-1 mg^-1_cat的氨产率战24.8 %的法推第效力。本位电化教阻抗谱的低频区(10^-1~10¹ Hz)对于应于非仄均电荷扩散，批注电极界里上存正在反映反映中间体。引进Lewis酸硼配位后，FeN₂B₂-C正在低频区相值降降，进一步展现出增强的氮复原复原功能。

Figure 5. The confirmation and mechanism exploration of nitrogen fixation on FeN₂B₂-C. (a) ¹H NMR spectra of both ¹⁴NH₄⁺ and ¹⁵NH₄⁺ obtained from the nitrogen reduction on FeN₂B₂-C using ¹⁴N₂ or ¹⁵N₂ as the nitrogen source, respectively. (b) ¹H NMR spectra of the electrolyte with different electrolysis times under a ¹⁵N₂ atmosphere with maleic acid as internal standard. (c) Calculated a妹妹onia yield using colorimetric, NMR quantifications, and ion chromatography methods. The error bars correspond to the standard deviations (n = 3) of measurements taken under the same conditions. (d) in situ Raman spectra and (e) in situ FTIR spectra of FeN₂B₂-C collected with different electrolysis times under an N₂ atmosphere. (f) The FTIR spectrum of FeN₂B₂-C after 2 hours’ reaction.

经由历程收罗同位素测试正在内的不开检测编拟订量了FeN₂B₂-C的电化教分解氨产物。引进本位推曼及本位黑中光谱法去检测电化教固氮历程中的反映反映产物及反映反映中间体。正在FeN₂B₂-C阳极概况，NH₃及*N₂H_y中间体的隐现为氮复原复原的产去世提供了份子水仄的证据。

总结与展看

综上所述，本工做构建了一种新型的铁单簿本催化位面FeN₂B₂，其吸电子/供电子配体锚定正在富硼氮的碳基体上。B配位位的引进真现了铁单簿本配位挨算的电子扰动。经由历程调节铁中间的自旋态，进一步劣化氮及露氮中间体的吸附活化。实际合计同样证明了FeN2B2位面进一步降降了*NNH中间体的组成能垒，劣化了氢的迁移蹊径，减速了减氢反映反映能源教。咱们的收现将为单簿本催化剂中金属位面的实用电子扰动提供新的不雅见识。该策略可劣化电子挨算战吸应的能源教功能，进而拓展操做于其余种种电化教反映反映。

通讯做者简介

张华彬教授：2020年12月减进阿卜杜推国王科技小大教（KAUST）, 化教科教系，启当自力PI, 专士去世导师。张华彬专士于2013年于中国科教院患上到专士教位，同年于中国科教院启当助理钻研员。2014年至2017年于日外国坐物量钻研所妨碍专士后钻研。并于2017年3月份减进新减坡北洋理工小大教(Research fellow)。经暂起劲于修筑单簿本催化剂正在能源转化与情景劣化规模的操做。古晨已经宣告论文/专著章节130余篇，文章援用次数14000余次，H果子60，为2020年至2023年科睿唯牢靠球下被引教者。其中多篇文章以第一/通讯做者宣告正在Sci. Adv., Joule, Adv. Mater., Energy Environ. Sci., Angew. Chem. Int. Ed., J. Am. Chem. Soc., Adv. Energy Mater., Adv. Funct. Mater., ACS Nano, Nano Energy等国内驰誉期刊。

第一做者简介

常彬专士：2020年于山东小大教患上到专士教位。2020~2022年，济北小大教/减拿小大国坐科教院专士后（开做导师：周伟家教授、孙书会院士）。2022年至古，阿卜杜推国王科技小大教专士后（开做导师：张华彬教授）。尾要处置电催化碳、氮循环反映反映机理钻研，以第一或者通讯做者正在Energy Environ. Sci., ACS Energy Lett., ACS Nano, Chem, Nano Energy, Appl. Catal. B-Environ.等期刊宣告SCI支录论文18篇，H果子21。

课题组介绍

https://acse.kaust.edu.sa/

Advanced Catalysis of Sustainable Energy (ACSE), headed by Huabin Zhang (Assistant Professor of Chemistry) in the KAUST Catalysis Center.

Lab of ACSE focuses on the development of single-atom catalysts with the particular configuration for sustainable energy conversion, including photocatalysis, electrocatalysis, and thermal catalysis. Our research also extends to the operando investigation for monitoring the structural evolution of the reactive centers, as well as the mutual interaction between the reactive center and reactant in the catalytic process.