Innovative metal oxides (CaO, SrO, MgO) impregnated waste-derived activated carbon for biohydrogen purification

Abstract

In this work, a series of innovative metal oxide impregnated waste-derived activated carbons (MO/AC) was synthesized and used to purify the simulated biohydrogen based on the concept of CO2 removal from the gas stream. Effects of metal oxide types (CaO, SrO and MgO) and contents of the best metal oxides on the morphology and the CO2 adsorption capacity from the biohydrogen were investigated. It was found that both metal oxide types and contents played an important role on the adsorbent textural property and surface chemistry as well as the CO2 adsorption capacity. Among all synthesized adsorbent, the MgO-impregnated AC with 12 wt.% MgO (12MgO/AC) exhibited the highest CO2 adsorption capacity of around 94.02 mg/g. With this successive adsorbent, the biohydrogen with the H2 purity higher than 90 mol% can be achieved from the gas stream with 50 mol% CO2 for the first 2 min of adsorption period in a fixed bed reactor. The mechanism of CO2 adsorption occurred via a combined process of the physisorption and chemisorption. Besides, the 12MgO/AC exhibited a high recyclability after several repetitive adsorption/desorption cycles.

Exploring metal oxides for the hydrogen evolution reaction (HER) in the field of nanotechnology

“…So far, research efforts have continued to develop novel synthesis and functionalization techniques for metal oxide nanoparticles; their role in revolutionizing various industries and addressing pressing global challenges is increasingly apparent. 40–46 This cutting-edge research area holds great promise for a more sustainable and eco-friendly future.…”

The Influence of Oxidation and Nitrogenation on the Physicochemical Properties and Sorption Capacity of Activated Biocarbons Prepared from the Elderberry Inflorescence

“…Recently, much attention was devoted to the carbonaceous materials modified to contain different heteroatomic functional groups or metal ions in their structure. Modification of the precursors or activation products via nitrogenation, oxidation, impregnation or plasma and heat treatment permits obtaining materials of specific acidic–basic nature of the surface, hydrophobic–hydrophilic character as well as improved adsorption or catalytic properties [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Particularly promising are materials enriched in nitrogen and oxygen functional species because of wide possibilities of their application, both in various branches of industry as well as in environment protection [ 33 , 34 , 35 , 36 , 37 ], electrochemistry [ 15 , 38 , 39 ] and even modern medicine [ 32 ].…”