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Photoreduction of CO2 into the chemical feedstocks of fuels provides a green way to help solve both the energy crisis and carbon emission issues. Nevertheless, undesirable charge separation and migration, as well as rapid reverse charge recombination results in the unsatisfactory photocatalytic activity of most conjugated microporous polymers (CMPs). Herein, a pair of donor–acceptor (D-A) CMPs for CO2 photoconversion was developed through position isomerism by altering linkage sites. The results show that Py-D27F with 2,7-site linkage exhibits a completely conjugated structure and a large molecular dipole moment, thus significantly accelerating charge separation and transfer. As a result, Py-D27F achieves a higher yield of 320.9 μmol g−1 h−1 for CO2-to-CO photoreduction (without the addition of any photosensitizers and precious metals), which is about three-fold greater than that of Py-D36F (3,6-site linkage). This study provides a valuable idea for exploring outstanding CMP photocatalysts for the efficient processing of photocatalysis. [ABSTRACT FROM AUTHOR]

The reduction of CO2 is an important method to produce chemicals such as methanol, formic acid, formaldehyde, etc. In general, the reduction of CO2 is carried out at high temperatures and pressures with precious metals as catalysts, which is not favorable for industrial procedures. Thus, it will be very useful if researchers can find cost-effective catalysts for industrial application in CO2 reduction. In this work, commercially available ethylenediaminetetraacetic acid (EDTA) was tested as a cheap, non-toxic, and recyclable catalyst to initiate the N-carbonylation reaction of CO2 with amines. After screening various reaction parameters, including temperature, pressure, time, solvent, and reducing agent, the optimal reaction conditions were obtained: 80 °C, 2 MPa, 6 h, 50 mmol% catalyst dosage, 1 mL DMSO, and 1:1 molar ratio of amine to reducing agent. Notably, further studies confirmed that EDTA could also be effective for N-formylation even under ambient conditions (0.1 MPa and room temperature). The suitability of the catalyst for 26 kinds of substrates (including aliphatic amines, aromatic amines, and alicyclic amines) and its reusability were also investigated, with satisfactory results. Scale-up research has been performed effectively with a high conversion of amine (83%) to obtain the mono-formylated product selectively. Finally, the mechanism of the reaction between amine and CO2 has been proposed via control experiments and compared with results in the literature. [ABSTRACT FROM AUTHOR]

In this article, we present a study carried out through a qualitative-quantitative methodology of the exploratory-descriptive objective to investigate technologies that have obtained patents and contribute to the areas of architecture and urbanism, as well as information systems enhance the verification of the situation environmental and urban climate. In the investigation of these patents, we used a methodology divided into three stages: 1st – "Comprehensiveness", 2nd – "Specification", and 3rd – "Immersion" to identify the technologies described above and for the evaluation of the "positive climate" in urban areas, which are related to the reduction of environmental impacts as well as the reduction of CO2 levels. The analyses resulted in a universe of 38,413 patents that were divided by year. From the results of the patent mapping, we observed the advantages in the areas of technology, sustainability and energy obtained by countries such as China, USA, Europe and India. We obtained two units of patents granted, directly related to the theme of "climate positive", however, none focused on zero carbon emission measures, positive energy balance, environmental performance or clean energy strategies. Thus, there was a need to encourage vigorously the development of more and better tools to achieve the goal of a "positive climate". [ABSTRACT FROM AUTHOR]

Photocatalytic CO 2 reduction technology provides a promising approach to solve the energy and environmental problems. In this work, flower-like MnIn 2 S 4 microspheres were prepared by solvothermal method, and then calcined in air to obtain flower-like Mn doped In 2 O 3 (Mn:In 2 O 3) microspheres. Subsequently, Ni doped CdS (Cd 1-x Ni x S) nanocrystals were prepared and compounded with Mn doped In 2 O 3 to obtain Cd 1-x Ni x S/Mn:In 2 O 3 composite photocatalysts. It was found that Cd 0 · 96 Ni 0 · 04 S/Mn:In 2 O 3 had the best photocatalytic CO 2 reduction activity. The CO yield reached to 43.40 μmol g−1 in 3 h. The improved CO 2 reduction property were attributed to not only the increased light absorption capacity and the expanded surface area but also the enhanced charge separation efficiency that caused by the construction of Z-scheme heterostructure. The design and preparation of high-efficiency photocatalyst would be an effective way to promote the development of photocatalytic CO 2 reduction. • Flower-like Mn doped In 2 O 3 microspheres was synthesized and decorated with Cd 1-x Ni x S NCs. • Construction of Z-scheme heterostructure efficiently facilitated the charge separation. • The photocatalyst exhibited enhanced CO 2 reduction performance and good stability. [ABSTRACT FROM AUTHOR]

In this article, we present a study carried out through a qualitative-quantitative methodology of the exploratory-descriptive objective to investigate technologies that have obtained patents and contribute to the areas of architecture and urbanism, as well as information systems enhance the verification of the situation environmental and urban climate. In the investigation of these patents, we used a methodology divided into three stages: 1st – “Comprehensiveness”, 2nd – “Specification”, and 3rd – “Immersion” to identify the technologies described above and for the evaluation of the “positive climate” in urban areas, which are related to the reduction of environmental impacts as well as the reduction of CO2 levels. The analyses resulted in a universe of 38,413 patents that were divided by year. From the results of the patent mapping, we observed the advantages in the areas of technology, sustainability and energy obtained by countries such as China, USA, Europe and India. We obtained two units of patents granted, directly related to the theme of “climate positive”, however, none focused on zero carbon emission measures, positive energy balance, environmental performance or clean energy strategies. Thus, there was a need to encourage vigorously the development of more and better tools to achieve the goal of a “positive climate”.

The La-based perovskite (LaBO3) exhibits excellent optical properties. However, its valence band (VB) potential is not sufficiently positive to reach the oxidation potential required for the cleavage of chemical bonds (such as benzylic C-H), limiting its application in photocatalysis. Herein, we report the unconventional effects of heat activation on the reduction of the dissociation energy of benzylic C-H and aqueous H-O, thereby triggering the photocatalytic activity of La2CoxMn2-xO6 perovskites. Additionally, we demonstrate that photocatalysis is the main contributor to substrate conversion in the selective oxidation of toluene and reduction of CO2. Particularly, La2Co1.5Mn0.5O6 shows excellent performance with a product yield of 550.00 mmol gcat-1 and a toluene conversion of 22,866.67 µmol gcat-1 h-1. To the best of our knowledge, this is the highest reported product yield for the selective oxidation of benzylic C-H bond of toluene. Our findings provide insight into the specific role of heat activation in photocatalysis, which is crucial for breaking and overcoming the VB barrier to realize challenging reactions. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of the CO2 present in 0.1 M Ethanolamine (EA) aqueous solution at Palladium metal electrodes for the synthesis of ethyl carbamate (CH3CH2OC(O)NH2) is investigated. The application square wave potential regime of the carbon dioxide in (EA) to be reduced to an organic product. In addition to identifying optimal conditions for CO2 electrocatalysis reduction by the square wave potential regime, the potential value was between - 1.0 to 0.4 V with 1.4 V amplitude, the time of reaction was 4 hours and the frequency was 100 Hz. We have carried out reactions at various pH levels and different voltages in an alkaline environment to ensure optimal conditions for the production of ethyl carbamate. The palladium catalysts electrode has demonstrated high CO2 electro-reduction activity to the organic compound. The organic product was analyzed by cyclic voltammetry, NMR, UV spectrometry, FT-IR spectroscopy, TGA, and MS. The results suggest the reduction of CO2-saturated in 0.1 M ethanolamine to ethyl carbamate, C2H5OCONH2. The Faradaic Efficiency and current density of electro-convert CO2-saturated in ethanolamine to ethyl carbamate are 93% and 71 mA cm-2, respectively. [ABSTRACT FROM AUTHOR]

The green and clean sunlight-driven catalytic conversion of CO2 into high-value-added chemicals can simultaneously solve the greenhouse effect and energy problems. The controllable preparation of semiconductor catalyst materials and the study of refined structures are of great significance for the in-depth understanding of solar-energy-conversion technology. In this study, we prepared nitrogen-doped NiO semiconductors using a one-pot molten-salt method. The research shows that the molten-salt system made NiO change from p-type to n-type. In addition, nitrogen doping enhanced the adsorption of CO2 on NiO and increased the separation of photogenerated carriers on the NiO. It synergistically optimized the CO2-reduction system and achieved highly active and selective CO2 photoreduction. The CO yield on the optimal nitrogen-doped photocatalyst was 235 μmol·g−1·h−1 (selectivity 98%), which was 16.8 times that of the p-type NiO and 2.4 times that of the n-type NiO. This can be attributed to the fact that the nitrogen doping enhanced the oxygen vacancies of the NiOs and their ability to adsorb and activate CO2 molecules. Photoelectrochemical characterization also confirmed that the nitrogen-doped NiO had excellent electron -transfer and separation properties. This study provides a reference for improving NiO-based semiconductors for photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

The reduction of carbon dioxide with molecular hydrogen in the presence of Fe,Cr-containing catalysts supported on a Sibunit carbon material at 400°C and pressures of 0.1 and 8.5 MPa is studied. Carbon monoxide can selectively form over the catalysts with an Fe : Cr ratio of 1 : 5. C1–C4 hydrocarbons with a predominance of methane are produced together with CO upon a decrease in the content of chromium (5Fe–0.25Cr/C sample). Transmission electron microscopy shows that the 5Fe–5Cr/C catalyst contains iron chromite FeCr2O4 (spinel structural type) as the main phase preventing the reduction of iron and the formation of iron carbides, which, in turn, provide the formation of hydrocarbons in the reaction of CO2 and H2. [ABSTRACT FROM AUTHOR]

• The development of a photoelectrocatalytic reactor for the CO 2 reduction to hydrocarbon fuels. • Development of a new catalytic quaternary CuO-Graphene-ZnFe 2 O 4 -TiO 2 nanocomposite. • The different types of electrolytes in CO 2 ER reaction to support the interaction between the cathode surface and the outcoming final product. • A highest FE in each tests, especially 44.08 % in buffer electrolyte with UV-light. • The pH of the electrolyte and the proton existence impact on the FE (%) values. Research on the electrochemical reduction of CO 2 (CO 2 ER) and photoelectrochemical reduction of CO 2 (PEC-CO 2 R) to produce hydrocarbon fuels using renewable energy sources is gaining significant attention. In this study, we developed a new quaternary-structured catalytic material that has garnered interest in the catalysis industry. The performance of the catalysts was assessed by conducting CO 2 reduction tests using different electrolytes to support the interaction between the cathode surface and the final product. The selectivity and activity of the nanocomposites were evaluated based on the Faradaic efficiency (FE). Among all the tested nanocomposites, the CuO-Graphene-ZnFe 2 O 4 -TiO 2 nanocomposites (CGZFOT NCs) exhibited the highest FE in each test, particularly 44.08 % in the buffer electrolyte with UV light, which facilitated electron transfer for CO 2 reduction to methanol. The second highest FE value of 42.2 % was achieved when NaHCO 3 was used as the electrolyte under UV light. Notably, both the experimental conditions demonstrated high FE values in the absence of a light source. Furthermore, the presence of protons affects FE (%) values. NaHCO 3 , for instance, dissociates into Na+ and HCO 3 –, and acts as a carrier for hydrocarbon ions, enhancing absorption. The buffering capacity of the buffer electrolyte actively reacts with the produced hydroxide, promoting the mass transfer of CO 2 gas. This results in a high current density for redox reactions in sodium hydrocarbonate and a buffer electrolyte for all working electrodes (WEs). The choice of electrolyte significantly affects the performance of the catalyst; thus, we compared catalysts using only one electrolyte to determine whether their activity and selectivity are related to the catalyst structure and properties. The Z-scheme charge carrier mechanism of the quaternary CGZFOT NCs offered efficient separation and carrier of electron-hole pairs, and it was also found that the close-parallel interfacial connection led to improved photoelectrochemical CO 2 reduction (PEC-CO 2 R). In addition, we believe that our experiments provide a complete picture of the performance of catalysts in different environments. [ABSTRACT FROM AUTHOR]

A new-type boron carbide material has been used, as an electrocatalyst for the reduction of CO 2 to C2 and C1 based on the computational study. Within the current research, DFT was adopted to investigate the BC 3 nanoflake as an electrocatalyst for the reduction of CO 2. The optoelectronic attributes of the BC 3 nanoflake indicated that BC 3 nanoflake had a longer visible-light region and its band gap was 2.25 eV. Based on the spatial distribution of the LUMO and the HOMO, the introduction of boron extended the π network of BC 3 nanoflake, thereby dramatically increasing the photocatalytic efficiency. Additionally, we estimated the Gibbs free energy of each potential CO 2 reaction path onto BC 3 nanoflake. Based on the findings, CO 2 could reduce into CH 4 and CH 3 CH 2 OH with low limiting potentials of −0.41 V and −0.53 V, respectively. The current study can provide useful insights into the application of BC 3 nanoflake as an encouraging photocatalyst for the reduction reaction CO 2. [Display omitted] [ABSTRACT FROM AUTHOR]