combined spectroscopy and microscopy techniques to unravel the presence of residual oxygen in oxide-derived Cu electrocatalysts under CO 2RR conditions 17, 18, 19. Although the Pourbaix diagram of Cu indicates that oxidized Cu precursors should be readily reduced to Cu(0) at negative potentials 10, some experimental and theoretical studies have stated that Cu + species or mixed oxidation states of Cu (e.g., Cu 2+, Cu +, and Cu) are present in oxide- or hydroxide-derived Cu electrodes and are responsible for their high C 2+ selectivity 8, 11, 12, 13, 14, 15, 16. Derived Cu catalysts, formed from the in situ reactions of oxides, hydroxides, or other oxidized Cu precursors under the reducing potentials of CO 2RR, have attracted significant attention because they typically exhibit high selectivities toward C 2+ products 7, 8, 9. To date, Cu-based catalysts are the main force for the production of C 2+ products, owing to the *CO adsorption energy on Cu that favors the C–C coupling. Although significant progress has been made in the generation of single-carbon (C 1) products (e.g., carbon monoxide, formate, methane, and methanol), in which a product selectivity of above 80% and an industrial-level current density have been achieved 2, 3, 4, 5, the production of valuable multicarbon (C 2+) products (e.g., ethylene, ethanol, and n-propanol) using CO 2RR has remained a challenge 6. These findings establish correlations between Cu precursors, lattice strains, and catalytic behaviors, demonstrating the unique ability of operando characterization in studying electrochemical processes.Įlectrocatalytic CO 2 reduction reaction (CO 2RR) provides a versatile means of storing energy in chemical bonds while closing the anthropogenic carbon cycle 1. The high CO 2RR performance of some derived Cu catalysts is attributed to the combined effect of the small grain size and lattice strain, both originating from the in situ electroreduction of precursors. Theoretical calculations suggest that the tensile strain in Cu lattice is conducive to promoting CO 2RR, which is consistent with experimental observations. Furthermore, Cu(OH) 2- and Cu 2(OH) 2CO 3-derived Cu exhibit considerable tensile strain (0.43%~0.55%), whereas CuO-derived Cu does not. The results indicate that despite different kinetics, all three precursors are completely reduced to Cu(0) with similar grain sizes (~11 nm), and that oxidized Cu species are not involved in the CO 2RR. We combine operando X-ray diffraction and operando Raman spectroscopy to monitor the structural and compositional evolution of three Cu precursors during the CO 2RR. However, the origin of this selectivity and the influence of catalyst precursors on it are not fully understood. NOTE: Please don’t worry about the β(in radians), All the calculations are made such that you can enter β (i.e.Copper (Cu)-based catalysts generally exhibit high C 2+ selectivity during the electrochemical CO 2 reduction reaction (CO 2RR). Where, Dp = Average Crystallite size, β = Line broadening in radians, θ = Bragg angle, λ = X-Ray wavelength We can easily calculate the size of particles from Scherrer formula given: Which is why X-Ray spectroscopy is very useful technique for characterization of different types of materials. Hence X-Rays can penetrate inside the crystal structure of any material very easily and tells us the properties of material while coming out from that material. X-Rays are having wavelength between 0.01nm to 10nm. NOTE: Default value of wavelength of LASER is set is 0.15418 (Cu K-alpha), which is mostly used in the instruments. You should get the calculated results of the crystallite size in the “Calculated Result” field. 0.5) in desire columns of the calculator. STEP3: Now enter the measured Peak Position (i.e.
COPPER XRD FULL
STEP2: Now zoom on the area for which you want to calculate the crystallite size and note down the angle at which peak is shown and peak Full Width at Half Maximum (FWHM). STEP1: Open the XRD graph of the material, which is obtained from the instrument.
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