Tweaking Photo CO₂ Reduction by Altering Lewis Acidic Sites in Metalated‐Porous Organic Polymer for Adjustable H₂/CO Ratio in Syngas Production

Abstract

Herein, we have specifically designed two metalated porous organic polymers (Zn‐POP and Co‐POP) for syngas (CO+H2) production from gaseous CO2. The variable H2/CO ratio of syngas with the highest efficiency was produced in water medium (without an organic hole scavenger and photosensitiser) by utilizing the basic principle of Lewis acid/base chemistry. Also, we observed the formation of entirely different major products during photocatalytic CO2 reduction and water splitting with the help of the two catalysts, where CO (145.65 μmol g‐1 h‐1) and H2 (434.7 μmol g‐1 h‐1) production were preferentially obtained over Co‐POP & Zn‐POP, respectively. The higher electron density/better Lewis’s base nature of Co‐POP was investigated further using XPS, XANES, and NH3‐TPD studies, which considerably improve CO2 activation capacity. Moreover, the structure‐activity relationship was confirmed via in‐situ DRIFTS and DFT studies, which demonstrated the formation of COOH* intermediate along with the thermodynamic feasibility of CO2 reduction over Co‐POP while water splitting occurred preferentially over Zn‐POP.

Catching an Oxo Vanadate Porous Acetylacetonate Covalent Adaptive Catalytic Network that Renders Mustard-Gas Simulant Harmless

“…Similarly, core region N-1s XP spectra exhibited two deconvoluted peaks at 397.39 and 398.11 eV for TPA-POP suggesting the presence of neutral and oxidized N species because of the partial oxidation in air (Figure S6). A slight shift in higher energy binding energy is observed for both the core region C-1s and N-1s XP spectra in VO@TPA-POP , which is due to the incorporation of vanadium metal to TPA-POP . In the deconvoluted O-1s XP spectra of TPA-POP , two binding energy peaks located at 530.92 and 532.35 eV are attributed to C–O and CO, respectively (Figure S7), due to keto–enol tautomerization of the acac group.…”

“…28 A slight shift in higher energy binding energy is observed for both the core region C-1s and N-1s XP spectra in VO@TPA-POP, which is due to the incorporation of vanadium metal to TPA-POP. 5 In the deconvoluted O-1s XP spectra of TPA-POP, two binding energy peaks located at 530.92 and 532.35 eV are attributed to C−O and C�O, respectively (Figure S7), due to keto−enol tautomerization of the acac group. A slight shift in these two peaks is noted in the O-1s XP spectra of TPA-POP compared to the VO@TPA-POP with the indication of coordinative interaction of oxo-vanadium species to the acac ligand.…”

“…Moreover, the catalytic property can be tuned by introducing different metal sites to the polymeric framework as metals are well-known for their multivalence nature, especially the transition metals, to carry out various catalytic conversions . Previously, many researchers reported such metal-coordinated POP s which involved strong co-ordination between transition metal atoms such as Vanadium, Molybdenum, or other multivalence transition metals and organic linkers, for various catalytic reactions. , Thus, metal coordinated POP s consisting of active metal centers can form a bridge between POPs and metal organic frameworks (MOFs), which can be efficiently used as heterogeneous catalysts. , …”

Polyoxometalates Embedded into Covalent Triazine Frameworks Regulating Charge Transfer for Visible-Light-Driven Synthesis of Functionalized Sulfoxides and Detoxification of Mustard Gas Simulants

“…Similarly, there are three peaks at 284.6 eV (CC), 286.7 eV (C–N), and 288.4 eV (N–CN) in the C 1s XPS spectra of CTF (Figure S4). , Remarkably, the peak attributed to N–CN undergoes a higher binding energy shift due to the interaction between CTF and SiW 12 . Based on the results, the C 1s peak of SiW 12 -CTF showed red shift than the CTF, and Si 2p and W 4f peaks were blue shift than the SiW 12 , proving that the direction of electron transfer is from CTF to POM.…”

Construction of Ni/In2O3 Integrated Nanocatalysts Based on MIL-68(In) Precursors for Efficient CO2 Hydrogenation to Methanol

“…Therefore, the efficient conversion of CO 2 into value-added chemicals and fuels has drawn tremendous research attention. Methanol (CH 3 OH) is particularly attractive in the context of sustainable development as a precursor of various hydrocarbons and chemicals or even as a fuel itself. , Currently, three main strategies have been developed for CO 2 conversion to produce methanol, including photocatalysis, , electrocatalysis, − and thermal hydrogenation. Among them, CO 2 thermal hydrogenation using renewable energy sources or off-peak load H 2 is considered a viable, sustainable, and economical path to CO 2 utilization. , There is no doubt that heterogeneous catalysts play a critical role in the conversion of CO 2 into methanol due to the thermodynamic stability of the CO 2 molecules …”