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Glycine is a nonessential amino acid that plays a vital role in various biological activities. However, the conventional synthesis of glycine requires sophisticated procedures or toxic feedstocks. Herein, we report an electrochemical pathway for glycine synthesis via the reductive coupling of oxalic acid and nitrate or nitrogen oxides over atomically dispersed Fe–N–C catalysts. A glycine selectivity of 70.7% is achieved over Fe–N–C-700 at −1.0 V versus RHE. Synergy between the FeN3C structure and pyrrolic nitrogen in Fe–N–C-700 facilitates the reduction of oxalic acid to glyoxylic acid, which is crucial for producing glyoxylic acid oxime and glycine, and the FeN3C structure could reduce the energy barrier of *HOOCCH2NH2intermediate formation thus accelerating the glyoxylic acid oxime conversion to glycine. This new synthesis approach for value-added chemicals using simple carbon and nitrogen sources could provide sustainable routes for organonitrogen compound production.

The direct conversion of CO2to aromatics is of great strategic significance for the realization of carbon capture, utilization, and storage. However, the efficient conversion of CO2is still challenging due to its thermodynamic stability and chemical inertness. Herein, we report a ZnZrO solid solution prepared viadirect calcination using ZIF-8 and Zr(NO3)4·5H2O as precursors. Zn-Modified nano-hierarchical-pore HZSM-5 zeolite (Zn/Z5) was prepared viasteam-assisted crystallization using ZIF-8 as a sacrificial template and Zn source. The ZnZrO–Zn/Z5 composite catalyst was prepared by the physical mixing of the two components, which was used to catalyze the hydrogenation of CO2to aromatics. The physical and chemical properties of the catalysts were investigated using XRD, SEM, TEM, N2adsorption–desorption, ICP-OES, EDX, NH3-TPD, Py-IR, H2-TPR, XPS, CO2-TPD and other characterization methods. The effects of the ZnZrO calcination temperature, different Zn/Zr ratios, reaction conditions and the spatial distance between the ZnZrO and the Zn/Z5 zeolite on the catalytic performance of the catalytic hydrogenation of CO2to aromatics were investigated. The generalized gradient approximation (GGA) of density functional theory (DFT) simulation results showed that the adsorption and activation capacity of ZnZrO for CO2can be significantly improved with the increase of oxygen vacancies. Finally, the reaction mechanism was investigated by in situDRIFTS. Under the optimal reaction conditions, a CO2conversion of 15.2% and aromatic selectivity of 63.9% can be achieved over the ZnZr8O(350)–Zn/Z5 composite catalyst, and excellent catalytic stability was demonstrated.

Nanoscale polymer spherical and hollow structure HZSM-5 zeolites are prepared by hydrothermal and desilication–recrystallization methods. In addition, the crystallite size of two types of HZSM-5 can be easily controlled by changing H2O/Si mole ratio. The hollow structure HZSM-5 zeolite is formed, it is due to the 010 crystal plane is the most energetically favorable orientation in silicalite-1 and the Si species is first removed on this crystal plane. The properties of different morphology zeolites were characterized by means of XRD, SEM, TEM, NH3-TPD, N2isothermal adsorption–desorption and TG, and the catalytic performance of these two types of HZSM-5 in MTA reaction was investigated in a fixed-bed differential reactor. The results showed that the multilevel pore structure and suitable acid strength and more acid density were obtained in the hollow structure HZSM-5 zeolite. Therefore, the hollow HZSM-5 zeolite exhibited that higher catalytic lifetime and selectivity of aromatics than nanoscale polymer spherical HZSM-5 zeolite in MTA reaction. Furthermore, the Al distribution on the 010 crystal plane may change slightly during the process of fabricating hollow mesoporous, which leads to higher selectivity of p-xylene over hollow HZSM-5 than nanoscale polymer spherical HZSM-5 zeolite.

Cu-based catalysts are optimal for the electroreduction of CO2to generate hydrocarbon products. However, controlling product distribution remains a challenging topic. The theoretical investigations have revealed that the coordination number (CN) of Cu considerably influences the adsorption energy of *CO intermediates, thereby affecting the reaction pathway. Cu catalysts with different CNs were fabricated by reducing CuO precursors via cyclic voltammetry (Cyc-Cu), potentiostatic electrolysis (Pot-Cu), and pulsed electrolysis (Pul-Cu), respectively. High-CN Cu catalysts predominantly generate C2+products, while low-CN Cu favors CH4production. For instance, over the high-CN Pot-Cu, C2+is the main product, with the Faradaic efficiency (FE) reaching 82.5% and a partial current density (j) of 514.3 mA cm–2. Conversely, the low-CN Pul(3)-Cu favors the production of CH4, achieving the highest FECH4value of 56.7% with a jCH4value of 234.4 mA cm–2. In situ X-ray absorption spectroscopy and Raman spectroscopy studies further confirm the different *CO adsorptions over Cu catalysts with different CN, thereby directing the reaction pathway of the CO2RR.

Using bulk metals as catalysts to get high efficiency in electro-reduction of CO2is ideal but challenging. Here, we report the coupling of bulk metal electrodes and a ternary ionic-liquid-based electrolyte, 1-butyl-3-methylimidazolium tetrafluoroborate/1-dodecyl-3-methylimidazolium tetrafluoroborate/MeCN to realize highly efficient electro-reduction of CO2to CO. Over various bulk metal electrodes, the ternary electrolyte not only increases the current density but also suppresses the hydrogen evolution reaction to obtain a high Faradaic efficiency (FE) toward CO. FECOcould maintain ∼100% over a wide potential range, and metal electrodes showed very high stability in the ternary electrolyte. It is demonstrated that the aggregation behavior of the ternary electrolyte and the arrangement of two kinds of IL cations with different chain lengths in the electrochemical double layer not only increase the wettability to electrode and CO2adsorption but also extend the diffusion channel of H+, rendering the high current density and FECO.