Chemico-biological conversion of carbon dioxide

The unabated carbon dioxide(CO_(2))emission into the atmosphere has exacerbated global climate change,resulting in extreme weather events,biodiversity loss,and an intensified greenhouse effect.To address these challenges and work toward carbon(C)neutrality and reduced CO_(2)emissions,the capture and utilization of CO_(2)have become imperative in both scientific research and industry.One cutting-edge approach to achieving efficient catalytic performance involves integrating green bioconversion and chemical conversion.This innovative strategy offers several advantages,including environmental friendliness,high efficiency,and multi-selectivity.This study provides a comprehensive review of existing technical routes for carbon sequestration(CS)and introduces two novel CS pathways:the electrochemicalbiological hybrid and artificial photosynthesis systems.It also thoroughly examines the synthesis of valuable Cnproducts from the two CS systems employing different catalysts and biocatalysts.As both systems heavily rely on electron transfer,direct and mediated electron transfer has been discussed and summarized in detail.Additionally,this study explores the conditions suitable for different catalysts and assesses the strengths and weaknesses of biocatalysts.We also explored the biocompatibility of the electrode materials and developed novel materials.These materials were specifically engineered to combine with enzymes or microbial cells to solve the biocompatibility problem,while improving the electron transfer efficiency of both.Furthermore,this review summarizes the relevant systems developed in recent years for manufacturing different products,along with their respective production efficiencies,providing a solid database for development in this direction.The novel chemical-biological combination proposed herein holds great promise for the future conversion of CO_(2)into advanced organic compounds.Additionally,it offers exciting prospects for utilizing CO_(2)in synthesizing a wide range of industrial products.Ultimately,the present study provides a unique perspective for achieving the vital goals of“peak shaving”and C-neutrality,contributing significantly to our collective efforts to combat climate change and its associated challenges.

Genes functional identification and synthetic biology of natural products

Synthetic biology is one of the rapid developing scientific fields in recent years. Through synthetic biology,we have a better understanding of the natural synthesis process of natural products, which provides a favorable method to research the diversity of natural products, and also provides new tools for us to create new approach for producing natural products, we can synthesize compounds with different structures by artificial combination of different synthesis modules.

Characterization and catalytic activity of soft-templated Ni0-CeO_(2) mixed oxides for CO and CO_(2) co-methanation

Nanosized NiO,CeO_(2) and NiO-CeO_(2) mixed oxides with different Ni/Ce molar ratios were prepared by the soft template method.All the samples were characterized by different techniques as to their chemical composition,structure,morphology and texture.On the catalysts submitted to the same reduction pretreatment adopted for the activity tests the surface basic properties and specific metal surface area were also determined.NiO and CeO_(2) nanocrystals of about 4 nm in size were obtained,regardless of the Ni/Ce molar ratio.The Raman and X-ray photoelectron spectroscopy results proved the formation of defective sites at the NiO-CeO_(2) interface,where Ni species are in strong interaction with the support.The microcalorimetric and Fourier transform infrared analyses of the reduced samples highlighted that,unlike metallic nickel,CeO_(2) is able to effectively adsorb CO_(2),forming carbonates and hydrogen carbonates.After reduction in H2 at 400°C for 1 h,the catalytic performance was studied in the CO and CO_(2) co-methanation reaction.Catalytic tests were performed at atmospheric pressure and 300°C,using CO/CO_(2)/H_(2) molar compositions of 1/1/7 or 1/1/5,and space velocities equal to 72000 or 450000 cm^(3)∙h^(-1)∙gcat^(-1).Whereas CO was almost completely hydrogenated in any investigated experimental conditions,CO_(2) conversion was strongly affected by both the CO/CO_(2)/H_(2) ratio and the space velocity.The faster and definitely preferred CO hydrogenation was explained in the light of the different mechanisms of CO and CO_(2) methanation.On a selected sample,the influence of the reaction temperature and of a higher number of space velocity values,as well as the stability,were also studied.Provided that the Ni content is optimized,the NiCe system investigated was very promising,being highly active for the CO_(x) co-methanation reaction in a wide range of operating conditions and stable(up to 50 h)also when submitted to thermal stress.