High-Throughput Computational Screening of Metal–Organic Frameworks as High-Performance Electrocatalysts for CO₂RR

Metal–organic frameworks (MOFs) are considered as promising electrocatalytic materials for the carbon dioxide reduction reaction (CO2RR) due to their various excellent properties. Here, through multistep high-throughput screening of the Computation-Ready, Experimental (CoRE) MOF database, including structural rationality check, pore size screening, adsorption capacity prediction, open metal site identification, CO2 molecular activation capacity, and reaction path calculation, MOFs named GAFRUD, CAJQEL, and cg400449c are identified as potential catalysts for electrocatalytic CO2RR. Furthermore, based on density functional theory calculations, we propose that the polarity of the coordination bonds between the metal atoms and the coordination atoms in ligands has a significant impact on the activation of CO2 molecules, and the selectivity of HCOOH mainly depends on the adsorption energy difference between *HCOO and *COOH. This principle is further validated by the experimental results, which will provide guidelines for the rational design of MOF-based electrocatalysts for CO2RR

Sorption of tetracycline on biochar derived from rice straw under different temperatures

<div><p>Biochars produced from the pyrolysis of waste biomass under limited oxygen conditions could serve as adsorbents in environmental remediation processes. Biochar samples derived from rice straw that were pyrolyzed at 300 (R300), 500 (R500) and 700°C (R700) were used as adsorbents to remove tetracycline from an aqueous solution. Both the Langmuir and Freundlich models fitted the adsorption data well (R² > 0.919). The adsorption capacity increased with pyrolysis temperature. The R500 and R700 samples exhibited relative high removal efficiencies across a range of initial tetracycline concentrations (0.5mg/L-32mg/L) with the maximum (92.8%–96.7%) found for adsorption on R700 at 35°C. The relatively high surface area of the R700 sample and π–π electron-donor acceptor contributed to the high adsorption capacities. A thermodynamic analysis indicated that the tetracycline adsorption process was spontaneous and endothermic. The pH of solution was also found to influence the adsorption processes; the maximum adsorption capacity occurred at a pH of 5.5. These experimental results highlight that biochar derived from rice straw is a promising candidate for low-cost removal of tetracycline from water.</p></div

Effect of pH on adsorption capacity for tetracycline sorption on biochars.

<p>The concentration of tetracycline solution was 32 mg/L. Values are triplicate means ± SD. Letters indicate significant differences among treatments at a level of p < 0.05(Tukey test).</p

Pore structure of biochars derived from rice straw.

<p>Pore structure of biochars derived from rice straw.</p

Chemical composition of biochars derived from rice straw.

<p>Chemical composition of biochars derived from rice straw.</p

Pearson’s linear correlation coefficients between biochar characteristics and the <i>q</i>_e values obtained at different initial tetracycline concentration(<i>C</i>₀) at 25°C (n = 9).

<p>Pearson’s linear correlation coefficients between biochar characteristics and the <i>q</i>_e values obtained at different initial tetracycline concentration(<i>C</i>₀) at 25°C (n = 9).</p

Thermodynamic parameters for tetracycline sorption on biochars with initial concentration of tetracycline changing from 0.5 mg/L to 32 mg/L.

<p>Thermodynamic parameters for tetracycline sorption on biochars with initial concentration of tetracycline changing from 0.5 mg/L to 32 mg/L.</p

Effect of temperature on sorption coefficient (<i>K</i>_d) for tetracycline sorption on biochars with different initial tetracycline concentration.

<p>Effect of temperature on sorption coefficient (<i>K</i>_d) for tetracycline sorption on biochars with different initial tetracycline concentration.</p

Fourier transform infrared (FTIR) spectroscopic analysis of biochars derived from rice straw.

<p>Fourier transform infrared (FTIR) spectroscopic analysis of biochars derived from rice straw.</p

Langmuir and Freundlich model parameters for tetracycline sorption on biochars derived from rice straw at different adsorption temperatures (T).

<p>Langmuir and Freundlich model parameters for tetracycline sorption on biochars derived from rice straw at different adsorption temperatures (T).</p