Efficient Electrocatalytic CO2 Reduction to C2+ Alcohols at Defect-Site-Rich Cu Surface

•The CO2 reduction selectivity on Cu electrocatalysts was regulated by defect sites•The catalytic activity of with abundant defects illustrated DFT calculations•The faradaic efficiency ?70% to C2+ alcohols achieved in electroreduction Electrochemical carbon dioxide (CO2) is a promising approach solve both renewable energy storage and carbon-neutral cycle. In order improve the economic feasibility applications, electrocatalytic high activity, selectivity, stability toward multi-carbon products should be realized. When considering highly selective for electroreduction, catalysts have shown their potentials producing multiple systems, while among different has yet optimized. Here, we demonstrated rational strategy synthesize catalyst under CO-rich environment induce growth defect-rich sites that are best adsorption CO. During electrochemical process, these enabled surface density adsorbed ?CO intermediates, allowing tune pathways formation alcohols. upgrading excessive into value-added chemicals, exquisite control atomic structures obtain alcohol remained challenging due intrinsically favored ethylene at surface. Herein, demonstrate achieve We utilized construct stepped coverages intermediates bridge-bound adsorption, which allowed trigger Using this defect-site-rich catalyst, partial current densities > 100 mA·cm?2 flow-cell electrolyzer membrane electrode assembly (MEA) electrolyzer. A stable ?60% also obtained, ?500 mg production per cm2 during continuous 30-h operation. Reducing increasing atmospheric level critical tackling variety urgent environmental hazards, such as global warming. Powered solar or wind sources, reaction (CO2RR) produce chemicals/fuels store fulfill net-zero-emission goal.1Bushuyev O.S. De Luna P. Dinh C.T. Tao L. Saur G. van de Lagemaat J. Kelley S.O. Sargent E.H. What make how can it?.Joule. 2018; 2: 825-832Abstract Full Text PDF Scopus (518) Google Scholar desirable CO2-synthesized owing large market capacities.2Birdja Y.Y. Pérez-Gallent E. Figueiredo M.C. Göttle A.J. Calle-Vallejo F. Koper M.T.M. Advances challenges understanding conversion fuels.Nat. Energy. 2019; 4: 732-745Crossref (666) However, building alcohol-selective CO2RR remains challenge. Cu, one most effective products, typically favors hydrocarbons other than alcohols.3Jouny M. Lv J.J. Cheng T. Ko B.H. Zhu Goddard W.A. Jiao Formation carbon–nitrogen bonds monoxide electrolysis.Nat. Chem. 11: 846-851Crossref PubMed (74) To date, strategies Cu-based electrocatalysts, including geometric structure tuning,4Rahaman Dutta A. Zanetti Broekmann multicarbon activated mesh catalysts: an identical location (IL) study.ACS Catal. 2017; 7: 7946-7956Crossref (98) Scholar,5Zhuang T.-T. Liang Z. Seifitokaldani Li Y. Burdyny Che Meng Min Quintero-Bermudez R. et al.Steering post-C–C coupling enables alcohols.Nat. 1: 421-428Crossref (338) facet exposure,6Jiang K. Sandberg R.B. Akey Liu X. Bell D.C. Nørskov J.K. Chan Wang H. Metal ion cycling foil C–C reduction.Nat. 111-119Crossref (381) oxide-derived catalysts,7Ren D. Deng Handoko A.D. Chen C.S. Malkhandi S. Yeo B.S. Selective ethanol copper(I) oxide catalysts.ACS 2015; 5: 2814-2821Crossref (557) grain boundaries,8Chen B. Hu C. Zhang W. Zhao Z.J. Gong Grain-boundary-rich copper efficient solar-driven ethanol.J. Am. Soc. 2020; 142: 6878-6883Crossref (126) heteroatom doping/alloying,9Zhou Zou Yuan Xie al.Dopant-induced electron localization drives C2 hydrocarbons.Nat. 10: 974-980Crossref (429) Scholar,10Lv Shang Zhou Sham T.-K. Peng Zheng Electron-deficient Cu3Ag1 promoting alcohols.Adv. Energy Mater. 2001987Crossref (42) clusters11Xu Rebollar He Chong Sun C.-J. Muntean J.V. Winans R.E. al.Highly metallic clusters dynamically formed from atomically dispersed copper.Nat. 623-632Crossref (149) been widely studied. Although reach 90%,12Li Y.C. Nam D.-H. Lum Luo Ozden Hung S.-F. al.Cooperative CO2-to-ethanol via enriched molecule–metal interfaces.Nat. 3: 75-82Crossref (169) corresponding below 10 mA·cm?2. Recent reports local CO concentration suppressing deoxygenation HOCCH? favor alcohols.13Wang García Arquer F.P. C.-T. Y.-S. Wicks al.Efficient electrically powered suppression deoxygenation.Nat. 478-486Crossref (161) Scholar, 14Chen Yan Wu Wan Q. Ma heterogeneous dual active sites.Angew. Int. Ed. Engl. 59: 16459-16464Crossref (58) 15Lum Ager J.W. Sequential catalysis controls Cu.Energy Environ. Sci. 2935-2944Crossref Combined gas-diffusion electrodes, reached ?50% regime above industrially relevant performance metrics CO2-to-alcohol further improved. Controlling coverage, accomplished tandem design CO2RR,13Wang Scholar,15Lum enhance selectivity. report enable coverage pure catalysts—the generation defective synthesizing conditions (Figures 1A 1B). The species processing promote (designated Cu-DS, Figure 1C). Cu-DS converts efficiencies over contrast, flat surfaces without adsorbates Cu-C), C2H4 dominates product distribution 1D–1F). Furthermore, using ?200 mA·cm?2, synthesized paper controlled deposition method CO-bounded Cu(I) molecular complex precursor continuously delivered gas flow (Experimental Procedures). For comparison, same applied CuCl argon (Ar) grow Cu-C sample. X-ray diffraction (XRD) patterns obtained samples showed three characteristic peaks (JCPDS 04-0836), (111), (200), (220) planes, respectively (Figure 2A). chemical compositions metal oxidation states were investigated photoelectron spectroscopy (XPS, 2B). 2p spectra presented two main centered 932.2 952.1 eV, respectively, suggesting as-synthesized +1 0.16Kuang Han Co-embedded N-enriched mesoporous oxygen hydrogen evolution reactions.Adv. 1700193Crossref valence interrogated operando absorption (XAS) conditions. Unless specifically noted, all voltages work referred reversible (RHE). At constant potential ?1.08 V, K-edge recorded 8 independent runs (i.e., scans × 9 s each). All near edge (XANES, Figures 2C 2D, left panels) matched reference (black curve) well peak position line shape but differed Cu2O (purple curve). No shifts observed CO2RR, confirming only contained Cu(0) species. Fittings extended fine (EXAFS, right panels, S1) environments standard foil, Cu. slight amplitude consistent larger aspect ratio bulk foil. then structural difference between transmission microscopy (TEM) analysis. Both had similar dendritic 2E 2F, panels), accord scanning (SEM) images S2 S3). High-resolution TEM (HRTEM) selected area (SAED) panels insets) revealed single-crystalline each dendrite. addition, dense strip structures, not Cu-c S4 S5). existence indicated Cu-DS.17Zhong Koch Scherer Walheim Hahn Schimmel Nanoscale twinned nanowire direct electrodeposition.Small. 2009; 2265-2270Crossref (80) estimation sites, off-axis holography, visualizes lattice boundaries,18Li Z.A. Tavabi A.H. Caron Jin Du Kovács Tian Farle Dunin-Borkowski Magnetic Skyrmion boundaries studied quantitative holography.Nano Lett. 17: 1395-1401Crossref (25) quantify polarization charge 2G 2H). Compared Cu-C, sample exhibited much more significant fluctuation negative positive dendrite 2I), higher Cu-C. gain insight intermediate catalysts, performed attenuated total reflection surface-enhanced infrared (ATR-SEIRAS, S6) Procedures).19Zhu Jiang Cai W.B. Shao Direct observation role bicarbonate anions surfaces.J. 139: 15664-15667Crossref (234) 20Jiang X.G. D.Y. Boosting formate wide window Pd 140: 2880-2889Crossref (204) 21Jiang tuning reduction.ACS Nano. 6451-6458Crossref (100) 22Zhu W.-B. probed through spectroscopy.ACS 682-689Crossref (110) 23Wang Golam Kibria M.G. Tan C.-S. Gabardo C.M. al.Catalyst synthesis favours faceting promotes fuels electrosynthesis.Nat. 98-106Crossref (157) downward band ?2,347 cm?1 S7), arising consumption interfacial range 0.2 ?1.2 V. bands ?2,070 attributed atop-bounded (labeled ?COL).19Zhu Scholar,22Zhu Scholar,24Nitopi Bertheussen Scott S.B. Engstfeld A.K. Horch Seger Stephens I.E.L. al.Progress perspectives aqueous electrolyte.Chem. Rev. 119: 7610-7672Crossref (1215) Scholar,25Chang Malkani Yang Xu Mechanistic Insights Electroreductive acetaldehyde products.J. 2975-2983Crossref (47) found species26Heyes J.M. Dunwell low overpotentials situ spectroscopy.J. Phys. 2016; 120: 17334-17341Crossref 27Yan Y.G. Q.X. Huo S.J. Osawa Ubiquitous probing ATR platinum group metal-electrolyte interfaces.J. 2005; 109: 7900-7906Crossref (124) 28Mojet B.L. Ebbesen S.D. Lefferts Light interface: water.Chem. 2010; 39: 4643-4655Crossref (203) 29Gunathunge Ovalle V.J. Janik M.J. Waegele M.M. Existence electrochemically inert population electrodes alkaline pH.ACS 8: 7507-7516Crossref (87) 30Raval Parker S.F. Pemble M.E. Hollins Pritchard Chesters M.A. FT-rairs, EELS LEED studies Cu(111).Surf. 1988; 203: 353-377Crossref (141) 31Chou T.-C. Chang C.-C. Yu H.-L. W.-Y. Dong C.-L. Velasco-Vélez J.-J. Chuang C.-H. L.-C. Lee J.-F. J.-M. state ethylene.J. 2857-2867Crossref (147) ?COB) 1,796–1,839 cm?1, ?0.3 V S7A). ?COB absent whole S7B). conducted ATR-SEIRAS measurements S8). Hence, hypothesized configuration may arise surfaces, namely, surface-enabled configurations ?COL ?COB, variation coverage.30Raval Scholar,32Radnik Ernst H.-J. Adsorption geometries Cu(211).J. 1999; 110: 10522-10525Crossref (12) Scholar,33Salimon Hernández-Romero R.M. Kalaji dynamics linear bridge Cu.J. Electroanal. 2002; 538–539: 99-108Crossref (27) confirm hypothesis, first functional theory (DFT) calculations. usually adopts close-packed face-centered cubic (fcc) structure, where exposed Cu(111), (110), Along defects, mismatches likely introduced.34Verdaguer-Casadevall C.W. Johansson T.P. McKeown J.T. Kumar Kanan M.W. Chorkendorff I. Probing electrocatalysts.J. 137: 9808-9811Crossref (377) 35Feng Fan Grain-boundary-dependent activity.J. 4606-4609Crossref (443) 36Feng grain-boundary-activity correlation nanoparticles.ACS Cent. 169-174Crossref (270) 37Wang Zeng Gao Maxson Raciti Giroux Pan Greeley Tunable intrinsic strain two-dimensional transition electrocatalysts.Science. 363: 870-874Crossref model having our calculations (Supplemental Experimental Procedures; S9A). denoted Cu’(101) 3A S9B), wherein Cu’ indicates mismatch, exposes Cu(111)-like Cu(100)-like direction mismatched atoms boundary. Given CO? low-coordinated steps,38Tao Dag L.W. Butcher D.R. Bluhm Salmeron Somorjai G.A. Break-up coverage.Science. 327: 850-853Crossref (394) 39Eren Zherebetskyy Patera L.L. C.H. Africh Activation Cu(111) decomposition nanoclusters driven adsorption.Science. 351: 475-478Crossref (167) 40Wang Tang Lin al.Self-selective reduction.Joule. 1927-1936Abstract step-like possible. kinds stepped-Cu’(101) considered, i.e., stepped-Cu’(101)-A 3B) stepped-Cu’(101)-B 3C S10), respectively. examine stabilities flat-Cu’(101) surface, calculated respective energies 3D). B decreased 101 40 meV·Å?2 along increase coverage. 0.50 monolayer, close (36.91 meV·Å?2) (34.25 meV·Å?2). Note reduced lateral interactions would (?0.58 monolayer). becomes less stable. concluded favorable environment, characterization results. capability stepped-site-rich providing With ?COOH crucial converting CO,41Peterson A.A. Abild-Pedersen Studt Rossmeisl How catalyzes hydrocarbon fuels.Energy 1311-1315Crossref (1876) 42Peterson Activity descriptors methane transition-metal catalysts.J. 2012; 251-258Crossref (976) 43Cheng Xiao Reaction mechanisms reductionof Cu(100) 298 K quantum mechanics free explicit water.J. 138: 13802-13805Crossref (218) theoretical limiting (|UL|) terms coordination numbers (CNs) summarized 3E). required eliminate barrier rate-limiting step diagram 3F 3G examples). As irregular containing CNs, A, B, labeled green triangles, red blue squares, regular contain CN = 9, These results indicate 6-CN 7-CN (with |UL| ranging 0.71 0.43 eV) CO2-to-CO activities 8-CN 9-CN 1.07 0.69 eV). 0.86 0.94 inferior 6 7. boundary do exhibit Cu’(101), compared scenario S11). Thus, expected lead increased concentration, increases oxygenate production.15Lum S12 Supplemental Procedures) suggest enhances suppresses formation. evaluated H-type cell CO2-saturated 0.1 M KHCO3 electrolyte major liquid included (CH3CH2OH) n-propanol (CH3CH2CH2OH), confirmed 1H-nuclear magnetic resonance (NMR, S13). FE values 53% 18%, 4A), outperforming state-of-the-art (Table S1).7Ren Scholar,12Li 13Wang Scholar,44Lee Park importance Ag-Cu biphasic ethanol.ACS 8594-8604Crossref (191) 45Geioushy R.A. Khaled Hakeem A.S. Alhooshani Basheer High graphene/Cu2O 785: 138-143Crossref (49) 46Zhao Quan overpotential Cu/carbons fabricated organic framework.ACS Appl. Interfaces. 9: 5302-5311Crossref 47Hoang T.T.H. Verma S.C. Fister T.T. Timoshenko Frenkel A.I. Kenis P.J.A. Gewirth Nanoporous copper-silver alloys additive-controlled electrodeposition 5791-5797Crossref (384) 48Li F.P.G. al.Binding site diversity 141: 8584-8591Crossref (181) 49Ma Sadakiyo Heima Yamauchi One-step electrosynthesis electrolyzer.J. Power Sources. 301: 219-228Crossref (297) 50Gabardo O’Brien C.P. Edwards J.P. McCallum Sinton Continuous concentrated assembly.Joule. 2777-2791Abstract (154) distinctively 4B), produced maximum 60% ?1.23 commercial Cu2O-derived NH3 agent did show S14 S15). alcohol-to-ethylene 0.128 10.3, over-80-fold products. areas (ECSAs) determined double-layer capacitances (Cdl, S16), 1.08 (for Cu-DS) 1.06 mF·cm?2 Cu-C). ECSA excluded contribution enhanced Cu-DS. interaction surrounding water molecules protons, suggested agreement findings. facilitated form verify cells S17). expected, ?55% ?15% n-propanol, comparable those CO2RR. CORR production, used gas-diffusion-electrode-based system equipped mass transfer. ?1.05 potential, overall 180 mA·cm–2, 4C 4D). highest 52% 15% ?0.95 mA·cm–2 optimal H-cells, pH systems. detailed displayed Tables S2–S5, retained its cells. 58% 78.3 ?1.02 obtained. cells, ?54 folds productive conversion, operated test 5-cm2Birdja MEA full-cell voltage ?3.5 4E). operation 4F S18; Table S6), ?400 500 S19). ?20%, indicating ?1.2× prior reports.12Li Scholar,13Wang After examined S20), features retained. holographic post-CO2RR S20 S21) preserved pre-CO2RR still findings stabilize defects. summary, prepare This condition stabilizing energy, greatly pathways. spectroscopies calculations, and, thereby, result, electrocatalyst achieves H-cell system. electrolyzers, mA cm?2 67% efficiency. electrolyzer, efforts contributed developing carbonate-formation-free systems efficiency, exciting opportunities will fuel electroproduction productivity, single-pass utilization.