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Abstract The directional transformation of carbon dioxide (CO2) with renewable hydrogen into specific carbon-heavy products (C6+) of high value presents a sustainable route for net-zero chemical manufacture. However, it is still challenging to simultaneously achieve high activity and selectivity due to the unbalanced CO2 hydrogenation and C–C coupling rates on complementary active sites in a bifunctional catalyst, thus causing unexpected secondary reaction. Here we report LaFeO3 perovskite-mediated directional tandem conversion of CO2 towards heavy aromatics with high CO2 conversion (> 60%), exceptional aromatics selectivity among hydrocarbons (> 85%), and no obvious deactivation for 1000 hours. This is enabled by disentangling the CO2 hydrogenation domain from the C-C coupling domain in the tandem system for Iron-based catalyst. Unlike other active Fe oxides showing wide hydrocarbon product distribution due to carbide formation, LaFeO3 by design is endowed with superior resistance to carburization, therefore inhibiting uncontrolled C–C coupling on oxide and isolating aromatics formation in the zeolite. In-situ spectroscopic evidence and theoretical calculations reveal an oxygenate-rich surface chemistry of LaFeO3, that easily escape from the oxide surface for further precise C–C coupling inside zeolites, thus steering CO2-HCOOH/H2CO-Aromatics reaction pathway to enable a high yield of aromatics.

Abstract Enzymes achieve high catalytic activity with their elaborate arrangements of amino acid residues in confined optimized spaces. Nevertheless, when exposed to complicated environmental implementation scenarios, including high acidity, organic solvent and high ionic strength, enzymes exhibit low operational stability and poor activity. Here, we report a metal-organic frameworks (MOFs)-based artificial enzyme system via second coordination sphere engineering to achieve high hydrolytic activity under mild conditions. Experiments and theoretical calculations reveal that amide cleavage catalyzed by MOFs follows two distinct catalytic mechanisms, Lewis acid- and hydrogen bonding-mediated hydrolytic processes. The hydrogen bond formed in the secondary coordination sphere exhibits 11-fold higher hydrolytic activity than the Lewis acidic zinc ions. The MOFs exhibit satisfactory degradation performance of toxins and high stability under extreme working conditions, including complicated fermentation broth and high ethanol environments, and display broad substrate specificity. These findings hold great promise for designing artificial enzymes for environmental remediation.

High activity and productivity of MoVNbTeOx catalyst are challenging tasks in oxidative dehydrogenation of ethane (ODHE) for industrial application. In this work, phase-pure M1 with 30 wt% CeO2 composite catalyst was treated by oxygen plasma to further enhance catalyst performance. The results show that the oxygen vacancies generated by the solid-state redox reaction between M1 and CeO2 capture active oxygen species in gas and transform V4+ to V5+ without damage to M1 structure. The space-time yield of ethylene of the plasma-treated catalyst was significantly increased, in which the catalyst shows an enhancement near ∼100% than that of phase-pure M1 at 400 °C for ODHE process. Plasma treatment for catalysts demonstrates an effective way to convert electrical energy into chemical energy in catalyst materials. Energy conversion is achieved by using the catalyst as a medium.

Spontaneous monodispersion of active species and their stabilization in reductive atmospheres remain a challenge in catalytic syngas chemistry. Here the authors demonstrate that syngas-to-aromatic conversion can be significantly accelerated by the spontaneously monodispersed Fe in ZnCr2O4 spinel.

Abstract Cu‐based catalysts exhibit excellent performance in hydrogenation reactions. However, the poor stability of Cu catalysts under high temperatures has restricted their practical applications. The preparation of stable Cu catalysts supported by SiO2 with strong metal–support interaction (SMSI) has thus aroused great interest due to the high abundance, low toxicity, feasible processability, and low cost of SiO2. The challenge in the construction of such SMSI remains to be the inertness of SiO2. Herein, a simple and scalable method is developed to prepare 2D silica (2DSiO2) supported Cu catalysts with SMSI by carefully manipulating the topological exfoliation of CaSi2 with CuCl2 and thereafter calcination. The prepared Cu‐2DSiO2 catalysts with the unique encapsulated Cu nanoparticles exhibit excellent activity and long‐term stability in high‐temperature CO2 hydrogenation reactions. This feasible and low‐cost solution for stabilizing Cu catalysts might shed light on their realistic applications.

Enhancing the intrinsic activity and space time yield of Cu based heterogeneous methanol synthesis catalysts is one of the major topics in CO2 hydrogenation. Here the authors develop a highly active inverse catalyst composed of fine ZrO2 islands dispersed on metallic Cu nanoparticles.

The steam reforming of methane (SRM) reaction is a significant process for efficient syngas generation and for promising distributed hydrogen production. In this work, a series of LaNiO3 oxides were prepared using the Pechini method, calcined from 600 °C to 900 °C and tested for the SRM reaction. Fresh, reduced, and used samples were characterized using STA-MS-FTIR, in situ and ex situ XRD, N2 physical adsorption, H2-TPR, TEM, TPO, and Raman. The results show that LaNiO3 begins to crystallize at about 550 °C, and the increase in calcination temperature results in the following differences in the properties of the LaNiO3 samples: larger LaNiO3 grains, smaller specific surface area, higher reduction temperature, smaller Ni0 grains reduced from the bulk phase, and stronger metal–support interaction. The maximum CH4 conversion could be achieved over LaNiO3 calcinated at 800 °C. In addition, the effect of steam-to-carbon ratio (S/C) on the performance of the SRM reaction was studied, and a S/C of 1.5 was found to be optimal for CH4 conversion. Too strong a metal–support interaction and too much unreacted steam causes a loss of catalytic activity. Finally, it was also proved using TPO and Raman that an increase in calcination temperature improves the carbon deposition resistance of the catalyst.

Ethylene is mainly produced by steam cracking of naphtha or light alkanes in the current petrochemical industry. However, the high-temperature operation results in high energy demands, high cost of gas separation, and huge CO2 emissions. With the growth of the verified shale gas reserves, oxidative dehydrogenation of ethane (ODHE) becomes a promising process to convert ethane from underutilized shale gas reserves to ethylene at a moderate reaction temperature. Among the catalysts for ODHE, MoVNbTeOx mixed oxide has exhibited superior catalytic performance in terms of ethane conversion, ethylene selectivity, and/or yield. Accordingly, the process design is compact, and the economic evaluation is more favorable in comparison to the mature steam cracking processes. This paper aims to provide a state-of-the-art review on the application of MoVNbTeOx catalysts in the ODHE process, involving the origin of MoVNbTeOx, (post-) treatment of the catalyst, material characterization, reaction mechanism, and evaluation as well as the reactor design, providing a comprehensive overview of M1 MoVNbTeOx catalysts for the oxidative dehydrogenation of ethane, thus contributing to the understanding and development of the ODHE process based on MoVNbTeOx catalysts.

Composite catalysts of mixed metal oxides were prepared by mixing a phase-pure M1 MoVNbTeOx with anatase-phase TiO2. Two methods were used to prepare the composite catalysts (the simple physically mixed or sol-gel method) for the improvement of the catalytic performance in the oxidative dehydrogenation of ethane (ODHE) process. The results showed that TiO2 particles with a smaller particle size were well dispersed on the M1 surface for the sol-gel method, which presented an excellent activity for ODHE. At the same operating condition (i.e., the contact time of 7.55 gcat·h/molC2H6 and the reaction temperature of 400 °C), the M1-TiO2-SM and M1-TiO2-PM achieved the space time yields of 0.67 and 0.52 kgC2H4/kgcat/h, respectively, which were about ~76% and ~35% more than that of M1 catalyst (0.38 kgC2H4/kgcat/h), respectively. The BET, ICP, XRD, TEM, SEM, H2-TPR, C2H6-TPSR, and XPS techniques were applied to characterize the catalysts. It was noted that the introduction of TiO2 raised the V5+ abundance on the catalyst surface as well as the reactivity of active oxygen species, which made contribution to the promotion of the catalytic performance. The surface morphology and crystal structure of used catalysts of either M1-TiO2-SM or M1-TiO2-PM remained stable as each fresh catalyst after 24 h time-on-stream tests.

The oxidative dehydrogenation of propane by CO2 (CO2-ODHP) can potentially fill the gap of propylene production while consuming a greenhouse gas. Here, the authors identify non-precious FeNi and precious NiPt catalysts supported on CeO2 as promising catalysts for CO2-ODHP and dry reforming, respectively, in flow reactor studies.

The "maker" movement is gaining widespread attention, especially in the field of laboratory education. Here we have built a low-cost, "do-it-yourself", open-source thermal conductivity cell detector (TCD) for chemical laboratory analysis, which is assembled from thermal conductivity gas sensor elements and 3D-printed flow cell parts based on a Raspberry Pi Pico microcontroller. An ADS1115 digital-to-analog converter (with 16-bit acquisition resolution) is used to acquire the electrical signal from the thermal conductivity sensor response via a Wheatstone bridge. The device is programmed to acquire data based on the open-source Thonny Micro Python IDE software via I[superscript 2]C communication. Temperature programming analysis (TPA) is an important technique to characterize heterogeneous catalysts; therefore, we apply the assembled TCD to characterize the reduction properties of commercial Cu/ZnO/Al[subscript 2]O[subscript 3] catalysts. The hydrogen temperature-programmed reduction (H[subscript 2]-TPR) profile of the commercial Cu/ZnO/Al[subscript 2]O[subscript 3] catalyst shows a broad peak in the range of 150--250 °C with a peak position at 213 °C, which is consistent with previous reports. The total amount of hydrogen consumed by the commercial catalyst during H[subscript 2]-TPR is 10.7 mmol/g[subscript cat], which can be calculated from the calibrated H[subscript 2] vol % TCD signal result and the peak area of the H[subscript 2]-TPR profile. The results show that the fabricated TCD detector exhibits excellent performance during the testing process and is capable of meeting research-grade applications. In summary, students will learn a wide range of skills in a hands-on learning environment of a chemistry laboratory course.