Zhang Y., Dong L.-Z., Li S. et al. · Nature Communications · 2021 · 6390
Open a family to keep every result attached to its sample, method and conditions.
Paraphrased for this database from the authors’ stated interpretations — never quoted verbatim — and kept separate from reported measurements.
Cu-DBC retains its framework phase, rod-like morphology and Cu oxidation-state distribution after CO2 electroreduction at -0.9 V vs RHE.
Caveat: Post-test characterisation is ex situ; in situ binding states are not directly measured.
p005 · ECR-to-CH4 performance · Fig. 2f; Supplementary Figs. 14-16 · Linked to 5 structured results
The gas-fed flow cell with a gas-diffusion layer improves CO2 mass transfer and enables high current densities for Cu-DBC.
Caveat: This is an application-electrode claim for a Cu-DBC/GDL composite electrode, not the pristine powder alone.
p003-p004 · ECR-to-CH4 performance · Supplementary Fig. 8 · Linked to 2 structured results
Cu-HHTP undergoes structural transition with Cu2O formation and morphology collapse after electrolysis, which may contribute to poor single-product selectivity.
Caveat: Cu-HHTP still gives substantial hydrocarbon FE; the transition is invoked to explain product distribution rather than total activity.
p006 · ECR performances · Supplementary Figs. 28-29 · Linked to 2 structured results
The computational analysis uses local fragment models extracted from crystal structures rather than periodic whole-framework or explicit solid/electrolyte interface models.
Caveat: Fragment approximation can miss long-range framework and interface effects; authors justify it by localisation of catalytic properties and large unit-cell size.
p009-p010 text layer · Reviewer response and Computational methods · Fig. R2 · Linked to 2 structured results
Cu-DBC with oxygen-coordinated Cu-O4 sites shows higher ECR-to-CH4 selectivity and activity than nitrogen-coordinated Cu-N4 comparator frameworks because the Cu-O4 sites have lower calculated energy barriers.
Caveat: DFT uses fragment models rather than periodic solid/electrolyte interfaces.
p001,p007 · Abstract; Discussion · Fig. 4 · Linked to 6 structured results
Charge delocalisation between Cu nodes and conjugated DBC ligands gives Cu-DBC measurable electrical conductivity that is higher than conventional non-conjugated MOFs, supporting electrocatalytic electron transfer.
Caveat: Peer review response acknowledges 1.2e-2 S m-1 is not remarkable among all cMOFs; comparison claim is limited to conventional MOFs without conjugated ligands.
p003 · Results · Fig. 1c · Linked to 1 structured result
Reversible redox behaviour of Cu-DBC suggests the Cu(I) redox state is probably the active site for eight-electron CH4 production during ECR.
Caveat: The active-state assignment is inferred from CV/redox behaviour, XPS, and DFT rather than directly observed operando.
p006 · Discussion · Supplementary Figs. 30-31 · Linked to 5 structured results
Names and aliases are kept exactly within the paper’s own identity model.
| Material | Composition | Structure context | Source |
|---|---|---|---|
| Cu-DBC | Not specifiedCu nodes; each Cu ion coordinated by two catechol groups to form Cu-O4 sites · dibenzo-[g,p]chrysene-2,3,6,7,10,11,14,15-octaol (8OH-DBC) | 3D · PristineFourfold interpenetrated dia topology with one-dimensional channels of about 1.0 nm; crystalline conductive MOF/cMOF. | p002-p003 · Results - Synthesis and characterizations of Cu-DBC electrocatalyst · Fig. 1a; Supplementary Fig. 1 |
| Cu-HHTPBrowse family: Cu₃(HHTP)₂ / Cu–HHTP | Not specifiedCu-O4 sites · 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) | 2D · Pristine2D conductive MOF comparator with Cu-O4 sites; post-test structural transition to Cu2O noted. | p005-p006 · ECR performances of crystalline single-site Cu electrocatalysts · Fig. 3a; Supplementary Fig. 17 |
| Cu-PPCOF | Not specifiedPhthalocyanine Cu-N4 sites plus linkage N sites · copper(II) octaaminophthalocyanine and pyrenediquinone (PDQ) | 2D · PristineCrystalline metallophthalocyanine covalent organic framework with phthalocyanine Cu-N4 sites. | p005-p007 · ECR performances; Discussion · Fig. 3a; Fig. 4a |
| Cu-TTCOF | Not specifiedPorphyrin Cu-N4 sites · Cu-TAPP and TTF-4CHO derived tetrathiafulvalene/porphyrin COF linkages | 2D · PristineCrystalline covalent organic framework containing metalloporphyrin Cu-N4 sites. | p005-p007 · ECR performances; Discussion · Fig. 3a; Fig. 4a |
| DFT fragment model of Cu-O4 site in Cu-DBC | fragment modelCu-O4 active site fragment · DBC fragment around Cu-O4 site | 0D · Model SystemReoptimised fragment extracted from Cu-DBC crystal structure; periodic calculations not performed because of large unit cell. | p007-p008 text layer · Computational methods; structure models · Fig. 4a; Supplementary coordinate section |
| DFT fragment model of phthalocyanine Cu-N4 site in Cu-PPCOF | fragment modelphthalocyanine Cu-N4 active site fragment · Cu-PPCOF phthalocyanine fragment | 0D · Model SystemReoptimised fragment extracted from Cu-PPCOF crystal structure. | p008 text layer · Computational methods; structure models · Fig. 4a; coordinate section |
| DFT fragment model of porphyrin Cu-N4 site in Cu-TTCOF | fragment modelporphyrin Cu-N4 active site fragment · Cu-TTCOF porphyrin fragment | 0D · Model SystemReoptimised fragment extracted from Cu-TTCOF crystal structure. | p007-p008 text layer · Computational methods; structure models · Fig. 4a; coordinate section |
Sample form, processing state and composition status define the context for measurements.
| Sample | Form and role | Processing and geometry | Source |
|---|---|---|---|
| Cu-DBC modified GDL-carbon paper electroderesearch_0757__mat__mat_cu_dbc | Electrode · Composite Sample · Composite | 10 mg catalyst dispersed in H2O/ethanol/Nafion ink; 50 uL ink drop-cast onto commercial GDL electrodecommercial gas-diffusion layer electrode / GDL-modified carbon paper · electrode area 0.25 cm2 | p006-p007 text layer · Electrochemical measurements · Supplementary Fig. 8 |
| as-synthesised Cu-DBC powder/nanorodsresearch_0757__mat__mat_cu_dbc | Powder · Target Sample · Pristine Framework | black product; solvent-exchanged in methanol for gas adsorption; stick-like nanorods 500 nm-1 um long and 50-100 nm wide | p002-p003 · Results · Fig. 1; Supplementary Figs. 1-7 |
| pressed Cu-DBC conductive sheetresearch_0757__mat__mat_cu_dbc | Pellet · Target Sample · Pristine Framework | conductive sample pressed into a sheet using a ton of pressure; I-V measured from -5.0 to 5.0 V at room temperature | p008 · Methods - Characterizations and instruments · Fig. 1c |
| Cu-HHTP modified GDL-carbon paper electroderesearch_0757__mat__mat_cu_hhtp | Electrode · Composite Sample · Composite | same ink and GDL electrode procedure as Cu-DBC comparator testscommercial gas-diffusion layer electrode / carbon paper · electrode area 0.25 cm2 | p005 · ECR performances · Supplementary Fig. 20 |
| as-prepared Cu-HHTP crystals/powderresearch_0757__mat__mat_cu_hhtp | Powder · Pristine Control · Pristine Framework | dark blue crystals washed with water and acetone and dried in air | p004-p005 text layer · Synthesis methods · Supplementary Fig. 17 |
| Cu-PPCOF modified GDL-carbon paper electroderesearch_0757__mat__mat_cu_ppcof | Electrode · Composite Sample · Composite | same ink and GDL electrode procedure as Cu-DBC comparator testscommercial gas-diffusion layer electrode / carbon paper · electrode area 0.25 cm2 | p005-p006 · ECR performances · Supplementary Fig. 22 |
| activated Cu-PPCOF powderresearch_0757__mat__mat_cu_ppcof | Powder · Pristine Control · Pristine Framework | grey-green powder collected at 70% yield; Soxhlet washed and evacuated at 80 deg C overnight | p006 text layer · Synthesis methods · Supplementary Fig. 19 |
| Cu-TTCOF modified GDL-carbon paper electroderesearch_0757__mat__mat_cu_ttcof | Electrode · Composite Sample · Composite | same ink and GDL electrode procedure as Cu-DBC comparator testscommercial gas-diffusion layer electrode / carbon paper · electrode area 0.25 cm2 | p005-p006 · ECR performances · Supplementary Fig. 23 |
| activated Cu-TTCOF powderresearch_0757__mat__mat_cu_ttcof | Powder · Pristine Control · Pristine Framework | sealed-tube product washed by filtration/Soxhlet and evacuated at 150 deg C overnight | p005 text layer · Synthesis methods · Supplementary Fig. 18 |
| Cu-O4 active-site DFT fragmentresearch_0757__mat__mat_model_cu_o4 | Model · Model System · Model | fragment extracted from Cu-DBC crystal structure and reoptimised | p007-p008 text layer · Computational methods · Fig. 4a; Supplementary coordinate section |
| phthalocyanine Cu-N4 active-site DFT fragmentresearch_0757__mat__mat_model_phthalocyanine_cu_n4 | Model · Model System · Model | fragment extracted from Cu-PPCOF crystal structure and reoptimised | p008 text layer · Computational methods · Fig. 4a; Supplementary coordinate section |
| porphyrin Cu-N4 active-site DFT fragmentresearch_0757__mat__mat_model_porphyrin_cu_n4 | Model · Model System · Model | fragment extracted from Cu-TTCOF crystal structure and reoptimised | p008 text layer · Computational methods · Fig. 4a; Supplementary coordinate section |