RESEARCH ARTICLE www.small-structures.com A MOF-Based Spatial-Separation Layer to Enable a Uniform Favorable Microenvironment for Electrochemical CO2 Reduction Xu Han, Ting Zhang,* Martí Biset-Peiró, Siqi Zhao, Sebastian Murcia Lopez, Kim Daasbjerg, Joan Ramon Morante, Jian Li,* and Jordi Arbiol* 1. Introduction Regulating the local microenvironment of active sites to increase their specific CO2 concentration and pH gradient, is a promising approach to optimize the Electrochemical CO2 reduction reaction electrochemical CO2 reduction reaction (eCO2RR). However, currently reported (eCO2RR) is a promising method to produce value-added chemicals and com- morphological strategies display an uncertainty to the compatibility and distri- modities, which can help to tackle the bution between catalytic sites and their microenvironment. Here, a uniform anthropogenic CO2 in the atmosphere spatial-separation metal–organic framework (MOF) layer between active sites and achieve a sustainable redox cycle for and bulk electrolyte is proposed, which enables each active site to locate in a energy storage and conversion.[1] Because similarly favorable microenvironment. Zinc oxide (ZnO) nanorods (NR), a rep- of the sluggish reaction kinetics of multi- resentative electrocatalyst for eCO2RR, is covered with a Zeolitic imidazolate proton and multi-electron transfer in the CO2 reduction process and the competitive framework-8 (ZIF-8) thin layer to serve as a model system. The prepared ZnO hydrogen evolution reaction (HER) occur- NR@ZIF-8 exhibits an enhanced Faradaic efficiency toward CO at a wide range of ring under aqueous conditions, substantial potentials and reaches a maximum FE of CO (85%) at 1.05 V versus reversible efforts have been invested toward the hydrogen electrode, which is one of the best records till date. Moreover, the design of new electrocatalysts with hydrophobic ZIF-8 layer protects ZnO against self-reduction. Such performance improved activity and selectivity.[2] In addition to optimization of the intrinsic cat- benefits from the porous ZIF-8 shell with high CO2 affinity, realizing efficient CO2 alytic activity, the local environment around access and retaining an increased local pH near ZnO active sites. catalysts, closely related to the transporta- tion of reaction species and intermediates, also plays an important role.[3] As the catalytic process has a synergistic effect between the active sites and the corresponding local microenvironment, judiciously inte- grating the intrinsic activity of catalysts with a favorable local X. Han, T. Zhang, J. Arbiol S. Zhao, K. Daasbjerg Advanced Electron Nanoscopy Novo Nordisk Foundation (NNF) CO2 Research Center (CORC) Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and Aarhus University BIST Gustav Wieds Vej 10C, 8000 Aarhus C, Denmark Campus UAB Bellaterra, 08193 Barcelona, Catalonia, Spain E-mail: ting.zhang@icn2.cat; arbiol@icrea.cat J. R. Morante Department of Physics X. Han, T. Zhang, M. Biset-Peiró, S. Murcia Lopez, J. R. Morante Universitat de Barcelona Energy Storage, Harvesting and Catalysis Group 08028 Barcelona, Catalonia, Spain Catalonia Institute for Energy Research (IREC) Sant Adrià de Besòs, 08930 Barcelona, Catalonia, Spain J. Li Laboratory of Renewable Energy Science and Engineering S. Zhao, K. Daasbjerg Institute of Mechanical Engineering Department of Chemistry/Interdisciplinary Nanoscience Center (iNANO) EPFL Aarhus University Station 9, 1015 Lausanne, Switzerland Langelandsgade 140, 8000 Aarhus C, Denmark E-mail: jian.li@epfl.ch The ORCID identification number(s) for the author(s) of this article J. Arbiol can be found under https://doi.org/10.1002/sstr.202200388. ICREA Pg. Lluís Companys 23, 08010 Barcelona, Catalonia, Spain © 2023 The Authors. Small Structures published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. DOI: 10.1002/sstr.202200388 Small Struct. 2023, 4, 2200388 2200388 (1 of 8) © 2023 The Authors. Small Structures published by Wiley-VCH GmbH 26884062, 2023, 8, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/sstr.202200388 by Readcube (Labtiva Inc.), Wiley Online Library on [08/11/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License www.advancedsciencenews.com www.small-structures.com environment is a wise strategy to achieve efficient catalytic all the active sites would be placed under a similarly favorable performance.[4] microenvironment, which would not only simplify their character- The accessibility to high concentrations of CO2 and the retain- ization and optimization, but also maximize the synergy between ability of increased local pH near the catalysts are two crucial them and their local microenvironment. parameters for the optimization of the local microenvironment.[5] To build a uniform spatial-separation microenvironment for Under high local CO2 concentration and elevated pH, the active each active site, introducing functional material with CO2 enrich- sites will promote the reduction of CO2 and inhibit HER.[6] For ment effect and ordered porous structure between the active sites example, E. H. Sargent’s group prepared nanoneedle-like Au tips and the bulk electrolyte is an appealing approach. Zeolitic imi- to achieve an enhanced local concentration of CO2 around the dazolate framework-8 (ZIF-8) possesses large specific surface nanometer-sized tips of the needle via field-induced reagent con- area, permanent porosity, and excellent CO2 enrichment capac- centration.[7] In contrast, Y. Surendranath and coworkers reported ity, making it of great potential to construct such a favorable that ordered mesostructured electrodes elevated the local pH to spatial-separation interface.[10] As a proof of concept, zinc oxide promote CO2-to-CO transformation.[8] Recently, Züttel’s group (ZnO) nanorods (NR), a representative electrocatalyst for reported that a highly porous electrocatalyst structure could eCO2RR,[11] were coated with a ZIF-8 thin sheath to serve as a strengthen the local pH effect, thus promoting CO selectivity model system. To avoid residual surfactants on the ZnO surface, by suppressing HER.[9] However, the aforementioned morpholog- the growth of ZIF-8 layer was achieved via an inorganic template- ical strategies, which construct a favorable microenvironment via assisted method. Compared to the pristine ZnO, the ZnO regulating the morphology of catalysts, bring more uncertainty to NR@ZIF-8 exhibited much higher activity and selectivity toward the compatibility and distribution between catalytic sites and CO at a wide range of potentials and reached a maximum microenvironment during the optimization process. To eliminate Faradaic efficiency of CO (FECO) of 85% at 1.05 V versus revers- this inconsistency between catalytic sites and the local environ- ible hydrogen electrode (RHE). This latest FECO value for ZnO ment, it is reasonable to utilize a spatial separation strategy to con- NR@ZIF-8 is one of the best values for ZnO-based catalysts struct a uniform and well-defined interface layer. In this scenario, reported till date. Moreover, the ZIF-8 thin layer kept the whole Figure 1. A) Schematic illustration of the formation process of ZnO NR@zeolitic imidazolate framework (ZIF-8) with scanning electron microscope (SEM) images of B) ZnO NR and C) ZnO NR@ZIF-8. X-ray diffraction (XRD) patterns of D) ZnO NR and ZnO NR@ZIF-8 and E) ZIF-8, and ZnO NR@ZIF-8. Small Struct. 2023, 4, 2200388 2200388 (2 of 8) © 2023 The Authors. Small Structures published by Wiley-VCH GmbH 26884062, 2023, 8, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/sstr.202200388 by Readcube (Labtiva Inc.), Wiley Online Library on [08/11/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License www.advancedsciencenews.com www.small-structures.com structure more stable during eCO2RR. Buffer electrolytes and wet- new diffraction peaks before 20° were assigned to ZIF-8 tability experiments proved that such enhancement was attributed (Figures 1D,E and S3, Supporting Information).[11a,11b,13] To to the increased pH and local CO2 concentration, resulting from further prove the uniform distribution of the ZIF-8 shell on the uniform spatial-separation interface. These results demon- the ZnO NR, transmission electron microscopy (TEM) charac- strate the excellence of constructing a uniform spatial-separation terization was carried out. Thanks to the difference of contrast interface layer to achieve the integration of active sites with a favor- in bright-field (BF) TEM and the high-angle annular dark-field able local microenvironment, which provides valuable insights for scanning TEM (HAADF–STEM) images (Figure 2A–C), we the rational design of future high-efficient electrocatalysts. could observe that the entire surface of ZnO NR was covered with a uniform shell, demonstrating that ZIF-8 was uniformly grown on the ZnO NRs surface. Elemental composition maps 2. Results and Discussion were further obtained by means of electron energy loss spec- troscopy (EELS) in STEM mode (Figure 2D). N and C elements ZnO NR@ZIF-8 was prepared by an inorganic template- were mostly located at the outer layer of the nanorod, while Zn assisted synthesis procedure (Figure 1A).[12] In brief, ZnO was distributed in the whole sample with relatively higher NR were first prepared and then used as self-sacrificed tem- concentration at the core area. It should be noted that N and plates for subsequent in situ growth of ZIF-8 in N-N-dimethyl- C elements were only found in the ZIF-8 shell, as part of the formamide (DMF) solution of 2-methylimidazole without any ligand, in line with the EELS mapping obtained on the ZIF-8 additional surfactant. Field-emission scanning electron micros- and ZnO NRs. Based on Fourier-transform infrared spectra, copy (FE-SEM) was used to characterize the morphology of the the typical vibration modes expected for ZIF-8 crystals appeared prepared ZnO NR@ZIF-8, ZnO, and ZIF-8 samples. In com- in the ZnO NR@ZIF-8 sample (Figure S4, Supporting parison to the pristine ZnO NR sample (Figure S1, Information). N2 adsorption–desorption measurements Supporting Information) and pure ZIF-8 (Figure S2, were performed to investigate the surface area influenced by Supporting Information), it was clearly observed that the the ZIF-8 layer on the as-prepared samples (Figure S5, ZnO NR@ZIF-8 inherited a rodlike structure from ZnO NR Supporting Information). The ZnO NR@ZIF-8 catalyst showed with an additional rough surface (Figure 1B,C). The crystallinity a typical type I adsorption/desorption isotherm curve and pos- of the as-prepared samples was confirmed by powder X-ray dif- sessed a high specific surface, indicating that ZnO NR@ZIF-8 fraction (XRD) measurements. Due to the different feature had numerous micropores inherited from the ZIF-8 shell. The peaks, the XRD pattern for ZnO NR@ZIF-8 exhibited two kinds high volume micropores of ZIF-8 shell could not only improve of distinct crystal structures. Except for the diffraction peaks CO2 affinities to enhance CO2 concentration but also provide after 30° corresponding to the XRD pattern of ZnO NR, the favorable channels for mass transfer between the active sites Figure 2. A,B) Bright-field transmission electron microscope (BF TEM) images, C,D) high-angle annular dark-field scanning TEM (HAADF–STEM) images, and representative electron energy loss spectroscopy (EELS) mappings of ZnO NR@ZIF-8. Small Struct. 2023, 4, 2200388 2200388 (3 of 8) © 2023 The Authors. Small Structures published by Wiley-VCH GmbH 26884062, 2023, 8, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/sstr.202200388 by Readcube (Labtiva Inc.), Wiley Online Library on [08/11/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License www.advancedsciencenews.com www.small-structures.com and the bulk electrolyte.[14] Additionally, the ZIF-8 layer could voltammetry (LSV) was tested to roughly evaluate the eCO2RR per- control the hydrophobicity of the interface. ZnO NR@ZIF-8 formance. Notably, ZnO NR@ZIF-8 presented a larger absolute with a water contact angle (CA) of 140° showed a more hydro- current density in CO2-saturated electrolyte (Figure S7B, phobic behavior than that of pure ZnO (water CA of 100°) Supporting Information) compared with that in Ar-saturated elec- (Figure S6, Supporting Information), which would inhibit trolyte. The absolute total current density of ZnO NR@ZIF-8 and HER and promote the enrichment of CO2. These results dem- ZnO NR increased significantly with respect to that of ZIF-8 at a onstrated that ZnO NRs were uniformly covered by porous ZIF- wide range of applied potentials, indicating the deterministic role 8 layer, which would create a favorable microenvironment for of ZnO as active sites for eCO2RR (Figure 3A). The fact that the each active site during eCO2RR. absolute total current density of ZnO NR @ZIF-8 was slightly The electrocatalytic activity of the different samples toward smaller than that of ZnO demonstrated that core–shell structure eCO2RR was investigated in a typical three-electrode H-cell under did not introduce additional active sites. CO2-saturated 0.5 M NaHCO3 solution. Before the electrochemical As expected, the ZnO NR@ZIF-8 exhibited much higher measurements, all electrodes were pretreated to obtain a steady FECO than other samples at a cathode potential from 1.15 to current at a constant potential of 0.70 V versus RHE for 0.80 V versus RHE (Figure 3B). At 1.05 V versus RHE, 30 min (Figure S7A, Supporting Information). Next, linear sweep FECO of ZnO NR@ZIF-8 was up to 85%, which is one of the Figure 3. A) Linear sweep voltammetry (LSV) curves acquired in CO2-saturated 0.5 M NaHCO3 electrolyte; B) FE of CO at various potentials; C) current density for CO production; D) FE of H2 at various potentials; E) current density for H2 production on ZIF-8, ZnO NR, and ZnO NR@ZIF-8; and F) FE of CO at various potentials on the mixture of ZnO NR and ZIF-8, and ZnO NR@ZIF-8 electrodes. Small Struct. 2023, 4, 2200388 2200388 (4 of 8) © 2023 The Authors. Small Structures published by Wiley-VCH GmbH 26884062, 2023, 8, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/sstr.202200388 by Readcube (Labtiva Inc.), Wiley Online Library on [08/11/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License www.advancedsciencenews.com www.small-structures.com best performances of ZnO-based catalysts (Table S1, Supporting NR dissolved totally in H2O (sample denoted as 0:1), no ZIF-8 Information). Figure 3C shows the potential-dependent CO partial shell structure was formed, as shown in the corresponding current densities calculated based on the current densities and cor- XRD patterns (Figure S9, Supporting Information). With the responding FECO. Considering the slightly smaller total current increase of H2O in DMF at a certain ratio (i.e., DMF/ density in absolute numbers, the higher CO partial current density H2O = 7:1, 2:1, 1:1), ZIF-8 could grow on the surface of ZnO of ZnO NR@ZIF-8 was attributed to the presence of the porous NRs, showing a well-defined interface between ZnO and ZIF-8. ZIF-8 layer, which enabled to provide a favorable microenvironment However, further increasing the ratio of H2O to DMF/ for ZnO active sites toward CO2 reduction. For the main side reac- H2O = 1:2, the skeleton structure of the NR disappeared tion HER, the decreased FE of H2 was observed when ZIF-8 shell (Figure S10, Supporting Information). The CO selectivity was coated on the surface of ZnO (Figure 3D). The smaller absolute (Figure S11, Supporting Information) obtained on different sam- partial H2 current densities for ZnO NR@ZIF-8 further supported ples demonstrated that the optimal ratio between DMF and H2O the suppression of HER due to the hydrophobic ZIF-8 layer was 7:1. Furthermore, the high local pH around the active sites (Figure 3E). To exclude that such enhancement was attributed to also benefits the catalytic activity for eCO2RR and suppressed the physical superposition of ZnO NR and ZIF-8, the electrocata- the HER.[5c,9] To verify the strengthened local pH effect enabled lytic activity of a physical mixture of ZnO NR and ZIF-8 was also by ZIF-8 layer, the eCO2RR of ZnO NR and ZnO NR@ZIF-8 sam- investigated. Obviously, ZnO NR@ZIF-8 showed a higher FECO at ples were performed in 0.5 M Na2HPO4 and 0.5 M NaHCO3, a wide range of applied potentials than that obtained by the physical respectively. These two kinds of electrolytes had different buffer mixture of ZnO NRs and ZIF-8 nanostructures (ZnO NR þ ZIF-8 capacities (0.5 M Na2HPO4 > 0.5 M NaHCO3). Compared to the sample) (Figure 3F), which indicated that the construction of a spa- performance in 0.5 M NaHCO3, the obtained FECO of ZnO NR tial-separation interface layer played a crucial role. was significantly reduced (Figure 4A) while the FE for H2 was To explore the relationship between the shell growth process enhanced (Figure 4B) in 0.5 M Na2HPO4. In contrast, ZnO and the corresponding catalytic activity, a series of core–shell struc- NR@ZIF-8 showed an almost equal FE for CO and H2 in both tures were prepared under different solvent composition condi- electrolytes (Figure 4C,D). Therefore, the nanoporous structure tions. A trade-off between the ZnO NR core and ZIF-8 shell of ZIF-8, to a certain degree, could hinder the neutralization pro- was observed during the construction of the spatial-separation cess for OH generated from cathodic reactions to keep a higher interface layer. When DMF was solely used as solvent (sample local pH than that in bulk electrolyte pH, thus suppressing the H2 denoted as 1:0), only small proportion of ZnO NR was covered evolution and promoting eCO2RR. by the ZIF-8 shell, which could not build an intact interface To evaluate the stability of the ZnO NR@ZIF-8 electrocatalyst, (Figure S8, Supporting Information). In the case of the ZnO we performed a 10 h durability test at a constant potential of Figure 4. A,B) Faradic efficiency for CO and H2 on ZnO NR and C,D) ZnO NR@ZIF-8 at various potentials in 0.5 M NaHCO3 and 0.5 M Na2HPO4, respectively. Small Struct. 2023, 4, 2200388 2200388 (5 of 8) © 2023 The Authors. Small Structures published by Wiley-VCH GmbH 26884062, 2023, 8, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/sstr.202200388 by Readcube (Labtiva Inc.), Wiley Online Library on [08/11/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License www.advancedsciencenews.com www.small-structures.com Figure 5. XRD patterns of A) ZnO NR@ZIF-8 and B) ZnO NR after stability test. High-resolution X-ray photoelectron spectroscopy (XPS) Zn 2p spectra of C) ZnO NR and D) ZnO NR@ZIF-8 after stability test. 1.05 V versus RHE. The outlet gas was analyzed every 30 min by and the interface between them was still clearly observed gas chromatography, while calculating the corresponding FE of (Figure S14, Supporting Information). All these results clearly CO. The current density of ZnO NR@ZIF-8 maintained a steady demonstrated that the ZIF-8 interface layer facilitated the ZnO value of approximately 13 mA cm2 with no significant decay active sites to participate in eCO2RR efficiently, thus stabilizing (Figure S12, Supporting Information), and the corresponding ZnO against reduction. FE of CO remained >80% during the 10 h test. As a comparison, the stability of bare ZnO NR was also performed. Interestingly, the color of bare ZnO NR electrode turned black from white, which 3. Conclusion was ascribed to the reduction of ZnO to Zn.[11a,15] In contrast, the In summary, a ZIF-8 shell has been introduced on the surface of color of ZnO NR@ZIF-8 electrode kept unchanged, indicating ZnO NRs by an in situ growth method, which provides a uni- that the higher local concentration of CO2 near ZnO active sites formly favorable microenvironment for eCO2RR. Compared to could promote eCO2RR while inhibiting its self-reduction pristine ZnO, the ZnO NR@ZIF-8 realizes a much higher (Figure S13, Supporting Information). FECO with a maximum of 85% at 1.05 V versus RHE. XRD, X-ray photoelectron spectroscopy (XPS), and TEM were Moreover, the ZIF-8 thin layer protects the ZnO NR and keeps used to obtain more accurate analysis of the structure and com- them stable during the eCO2RR. Such performance is attributed position of the electrocatalysts after the stability test. Unlike the to the following aspects: 1) the hydrophobic ZIF-8 shell layer ena- ZnO NR@ZIF-8, which only displayed the characteristic peaks of bles a higher CO2 concentration around the active sites and alle- ZnO and ZIF-8 (Figure 5A), the XRD spectra obtained on the viates the water penetration to ZnO surface; and 2) the highly ZnO NR after stability showed new emerging characteristic porous structure of ZIF-8 strengthens the local pH near ZnO, peaks belonging to metallic Zn (Figure 5B). Similarly, compared which further promotes the catalytic selectivity of eCO2RR via sup- to the XPS spectra obtained on ZnO NR@ZIF-8 after stability, pressing HER. This work provides a spatial-separation strategy to the XPS spectra obtained on the ZnO NR presented a much create a uniformly favorable local microenvironment for each stronger peak ascribed to the zero-valent zinc, in line with the active site, paving a new way for the improvement of eCO2RR. XRD results (Figure 5C,D). The morphology of ZnO NR@ZIF-8 did not change after the stability test, according to the results obtained by TEM and HAADF–STEM images. In Supporting Information addition, the EELS compositional maps showed that the ZIF-8 Supporting Information is available from the Wiley Online Library or from shell was still homogenously covering the ZnO NR surface the author. Small Struct. 2023, 4, 2200388 2200388 (6 of 8) © 2023 The Authors. Small Structures published by Wiley-VCH GmbH 26884062, 2023, 8, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/sstr.202200388 by Readcube (Labtiva Inc.), Wiley Online Library on [08/11/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License www.advancedsciencenews.com www.small-structures.com Acknowledgements L. Zhu, M. N. Ghazzal, J. Zhang, C.-H. Tung, L.-Z. Wu, Energy Environ. Sci. 2020, 13, 1326. The authors acknowledge funding from Generalitat de Catalunya [3] a) J.-J. Lv, R. Yin, L. Zhou, J. Li, R. Kikas, T. Xu, Z.-J. Wang, H. Jin, 2021 SGR 01581 and 2021 SGR 00457. X.H., T.Z., M.B.-P., S.M.L., X. Wang, S. Wang, Angew. Chem. Int. Ed. 2022, 61, e202207252; J.R.M., and J.A. acknowledge funding from the projects (Grant nos. b) J.-J. Lv, R. Yin, L. Zhou, J. Li, R. Kikas, T. Xu, Z.-J. Wang, H. Jin, PID2020-116093RB-C42 and -C43), funded by MCIN/AEI/10.13039/ X. Wang, S. Wang, Angew. Chem. 2022, 134, e202207252; 501100011033/and by “ERDF A way of making Europe”, by the “European Union”. This study was supported by MCIN with funding from c) H.-K. Lim, Y. Kwon, H. S. Kim, J. Jeon, Y.-H. Kim, J.-A. Lim, European Union NextGenerationEU (PRTR-C17.I1) and Generalitat de B.-S. Kim, J. Choi, H. Kim, ACS Catal. 2018, 8, 2420; Catalunya. ICN2 is supported by the Severo Ochoa program from d) S. E. Weitzner, S. A. Akhade, J. B. Varley, B. C. Wood, Spanish MCIN/AEI (Grant no. CEX2021-001214-S). S.Z. and K.D. acknowl- M. Otani, S. E. Baker, E. B. Duoss, J. Phys. Chem. Lett. 2020, 11, 4113. edge Novo Nordisk Foundation CO2 Research Center (Grant no. [4] a) C.-T. Dinh, F. P. García de Arquer, D. Sinton, E. H. Sargent, ACS NNF21SA0072700). ICN2 and IREC are funded by the CERCA Energy Lett. 2018, 3, 2835; b) J. Li, X. Han, D. Wang, L. Zhu, Programme/Generalitat de Catalunya. Part of the present work has been M.-H. Ha-Thi, T. Pino, J. Arbiol, L.-Z. Wu, M. Nawfal Ghazzal, performed in the framework of Universitat Autònoma de Barcelona Angew. Chem. Int. Ed. 2022, 61, e202210242; c) J. Li, X. Han, Materials Science PhD program. X.H. thanks China Scholarship D. Wang, L. Zhu, M.-H. Ha-Thi, T. Pino, J. Arbiol, L.-Z. Wu, Council for scholarship support (Grant no. 201804910551). M. Nawfal Ghazzal, Angew. Chem. 2022, 134, e202210242. [5] a) J. Li, G. Chen, Y. Zhu, Z. Liang, A. Pei, C.-L. Wu, H. Wang, H. R. Lee, K. Liu, S. Chu, Y. Cui, Nat. Catal. 2018, 1, 592; b) R. 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