A recent report from the United Nations has warned about the excessive CO2 emissions and the necessity of making efforts to keep the increase in global temperature below 2 °C. Current CO2 capture technologies are inadequate for reaching that goal, and effective mitigation strategies must be pursued. In this work, we summarize trends in materials development for CO2 adsorption with focus on recent studies. We put adsorbent materials into four main groups: (I) carbon-based materials, (II) silica/alumina/zeolites, (III) porous crystalline solids, and (IV) metal oxides. Trends in computational investigations along with experimental findings are covered to find promising candidates in light of practical challenges imposed by process economics.

A direct and effective approach is proposed to fabricate bimetallic phosphide Ni 2 P−Cu 3 P with controllable phase composition and distribution for catalytic hydrogen evolution reaction (HER). Unlike previously reported precursors, a porous Ni−Cu alloy incorporated with graphitic carbon (NiCuC) prepared via powder metallurgy is employed herein, and the generated Ni 2 P−Cu 3 P@NiCuC possesses a hierarchical porous structure and controllable phase composition due to the high porosity and tunable Ni/Cu ratio of the precursor. With an optimal Cu content of 30.0 wt %, the catalyst demonstrates the highest catalytic activity due to a synergistic interaction between different metallic phosphide sites and the facilitated mass transport. Meanwhile, density functional theory (DFT) calculation reveals that the atomic interaction of Ni 2 P− Cu 3 P substantially lower the activation barrier for enhanced HER catalytic activity. The powder metallurgy provides an approach for the design of bimetallic phosphide electrocatalysts for HER and other catalytic applications.

Crystalline manganese oxides have attracted the most attention in aqueous zinc-ion batteries due to their diverse nanostructures and low cost. However, extensive studies on amorphous manganese oxides are lacking. Herein, we report a mesoporous amorphous manganese oxide (UCT-1-250) as a cathode material with high capacity (222 mAh g–1), good cyclability (57% capacity retention after 200 cycles), and an acceptable discharge plateau (between 1.2 and 1.4 V). An approach to mechanistic studies was performed by comparison of UCT-1-250 and other crystalline manganese oxides through electrochemical, elemental, and structural analyses. An in situ conversion to ZnMn2O4 spinel phase after initial cycling contributes to the high performance. The irreversible capacity fading is due to the formation of the woodruffite phase.

We develop efficient synthetic methods to prepare various MnO2 structures and investigate their structure–property relationships as applied to the reverse Water Gas Shift (rWGS) reaction with a combination of experimental and theoretical tools.