Integrated capture and solar-driven utilization of CO2 from flue gas and air

•CO2 is captured from dilute sources and converted to synthesis gas using sunlight•PET plastic waste simultaneously upcycled glycolic acid during the process•A single encapsulated perovskite solar cell generates photovoltage power process•CO2 with amine/hydroxide, its reduction enabled by a molecular catalyst It becoming likely that net carbon zero future will rely on recycling of atmospheric CO2 produce sustainable fuels chemicals. Nevertheless, current processes for utilization use concentrated streams are not integrated capture sources. At same time, plastics critical protect our environment irreversible damages. We report an photoelectrochemical system captures exhaust stream concentrations ambient air directly converts it into (CO + H2, precursor industrial liquid fuel production) sunlight. This process coupled benefits concurrent valorization waste, which commodity chemical acid. The overall technology thus produces value-added chemicals industrially relevant powered solely sunlight at temperature pressure, important step toward circular economy. Integration technologies can lead way net-zero direct conversion chemically remains challenging due thermodynamic stability. Here, we demonstrate flue or syngas irradiation without any externally applied voltage. amine/hydroxide solution photoelectrochemically (CO:H2 1:2 [captured CO2], 1:4 [from simulated gas], 1:30 air]) perovskite-based photocathode containing immobilized Co-phthalocyanine catalyst. anode, plastic-derived ethylene glycol oxidized over Cu26Pd74 alloy uses as source, discarded electron donor, sole energy input. strategy opens new avenues carbon-neutral even negative upcycling technologies. Mitigation anthropogenic accumulation essential tackle climate change loss biodiversity.1Ritchie H. Roser M. Rosado P. 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Commun. 14675https://doi.org/10.1038/ncomms14675Crossref (548) amount determined 14.8 1.8 nmol cm−2 inductively plasma optical spectroscopy (ICP-OES) analysis, distribution confirmed scanning microscopy-energy dispersive X-ray (SEM-EDX) mapping (Figures S7 S8). cross-sectional SEM image showed ∼1.3 μm thick CoPcNH2@MWCNT layer deposited S9). then three-electrode configuration fabricated working electrode, Pt mesh counter Ag/AgCl (saturated NaCl) reference electrode. catholyte (pH 7.8–8.3), whereas anolyte 0.1 potassium sulfate (K2SO4, pH 7.6). compartments separated bipolar membrane. Cyclic voltammetry (CV) scans MEA, DEA, similar onset potentials around −0.40 −0.45 V vs. reversible hydrogen (RHE; 2A). Controlled potential electrolysis (CPE) h) H2) product 2B S10). H2 started −0.5 RHE, optimum faradaic efficiency (FECO) −0.7 RHE (46.2% 2.0%, 2B). CPE secondary (MEA DEA) resulted lower FECO 10.2% 1.7% 16.5% 1.5%, FE remained >95% 2C). Beside CoPcNH2, other unsubstituted although slightly reduced activities S11). Control experiments did and, consequently, produced no CPE, confirming role CCU control experiment MWCNT highlighting c-CO2RR species (NaHCO3 [Na2CO3]) (<3%, S12) overwhelming formation. To suppress formation, non-aqueous solvent explored. (as glycolate carbonate, 4) used, adding tetrabutylammonium tetrafluoroborate (TBABF4, 0.15 supporting electrolyte 20% v/v acetonitrile (MeCN) co-solvent ensure solution. CV −1.65 Fc/Fc+ 2D). Subsequent (for 10 −1.85 19.0% 1.4% 2E S13), 75%. Isotopic-labeling carbon-13C (13CO2) both (TEA/H2O) (NaOH/EG) labeled 13CO (gas-phase FTIR headspace), 2F). ICP-OES post-electrolysis provided 12.4 0.9 loading indicating minimal leaching S14). From studies, evident ideal range TEA/H2O NaOH/EG medium. irradiation, state-of-the art halide PVK photovoltaic employed open (VOC 1.1 V) absorb broad-range spectrum (360–750 nm).34Andrei Hoye R.L.Z. 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Hence, replaced less thermodynamically all experiments, sourced polyethylene terephthalate (PET) waste. electrodeposited Ni foam (Ni foam|Cu26Pd74, procedures) dark S17 S18) facilitate alkaline conditions.5Bhattacharjee Operating conditions setup external bias overlap individual curves (taken sun, Air Mass 1.5 Global [AM 1.5G] irradiation) foam|Cu26Pd74 “dark” conditions) configurations S19–S22). (Voverlap) 0.52 −0.85 media, respective densities 5.8 0.27 mA S20 S22). Accounting (VOC) (∼1.05 0.03 V, S23), experienced −0.53 −1.9 respectively (calculated Voverlap − VOC). These fall within 2E). Following establishment operating set (similar 2) 0.5 (KOH), being membrane introduces internal (∼0.35 −0.4 j 4.9 3A). Accordingly, stable photocurrent density 0.3 long-term photoelectrolysis 3B). After photoelectrolysis, detected 54.6 9.2 μmol 106.6 8.4 (FECO 34.1% 2.2% FEH2 70.3% 1.8%, 3C). rates steady throughout S24). turnover number (TONCO) reached 3,657 591 time 3D). 1H 13C-NMR post-photoelectrolysis unreacted S25). high-performance chromatography (HPLC) GA (85.8 16.2 cm−2; FEGA 92.5% 5.3%). above results indicate developed foam|Cu26Pd74||PVK|CoPcNH2@MWCNT concurrently (in TEA) investigate possibility employing real-world PET precursor, performed pre-treated bottle procedures). As HPLC contained ∼0.2 EG, disodium decomposition products KOH. sun comparable yields CO, observed model S26). demonstrates c-CO2 polymers. (Note 3E) 0.35 steady-state 0.18 3F). h, 5.2 16.4 0.6 18.2% 1.1%, 58.2% 4.0%) total 76% TONCO 347 74 3G 3H). S27). S28). 11.7 3.5 (FEGA 86% 11%, 3F), selectively analysis. sluggish, conductivity medium, affinity nature beneficial especially when ultra-dilute concentrations, apparent later sections. successful development implications coupling streams. Post-combustion plants well small point like automobile exhausts major contributor emissions. syngas. Industrial typically contains ∼15% 3%–5% O2 some SOx NOx impurities minimized wet scrubbing.39Sharif H.M.A. Mahmood Hussain Hou Y.N. Yang L.H. Zhao techniques SO2 removal: futu