Developing effective catalysts based on earth abundant elements is critical for CO₂ electroreduction. However, simultaneously achieving a high Faradaic efficiency (FE) and high current density of CO (j_CO) remains a challenge. Herein, we prepare a Mn single-atom catalyst (SAC) with a Mn-N₃ site embedded in graphitic carbon nitride. The prepared catalyst exhibits a 98.8% CO FE with a j_CO of 14.0 mA cm⁻² at a low overpotential of 0.44 V in aqueous electrolyte, outperforming all reported Mn SACs. Moreover, a higher j_CO of 29.7 mA cm⁻² is obtained in an ionic liquid electrolyte at 0.62 V overpotential. In situ X-ray absorption spectra and density functional theory calculations demonstrate that the remarkable performance of the catalyst is attributed to the Mn-N₃ site, which facilitates the formation of the key intermediate COOH^* through a lowered free energy barrier.

Sustainable and effective methods for biomass pretreatment and biomass cascade utilization are reviewed in this work.

Carbon molecular sieve (CMS) membranes with rigid and uniform pore structures are ideal candidates for high temperature- and pressure-demanded separations, such as hydrogen purification from the steam methane reforming process. Here, we report a facile and scalable method for the fabrication of cellulose-based asymmetric carbon hollow fiber membranes (CHFMs) with ultramicropores of 3–4 Å for superior H₂ separation. The membrane fabrication process does not require complex pretreatments to avoid pore collapse before the carbonization of cellulose precursors. A H₂/CO₂ selectivity of 83.9 at 130 °C (H₂/N₂ selectivity of >800, H₂/CH₄ selectivity of >5700) demonstrates that the membrane provides a precise cutoff to discriminate between small gas molecules (H₂) and larger gas molecules. In addition, the membrane exhibits superior mixed gas separation performances combined with water vapor- and high pressure-resistant stability. The present approach for the fabrication of high-performance CMS membranes derived from cellulose precursors opens a new avenue for H₂-related separations.

Amino-modification, as an ingenious strategy, was proposed for boosting CO ₂ electroreduction current density of Ni–N/C single-atom catalyst to industrial level.