Green CarbonPub Date : 2023-09-01DOI: 10.1016/j.greenca.2023.08.004
Yangsu Xie , Xinwei Wang
{"title":"Thermal conductivity of carbon-based nanomaterials: Deep understanding of the structural effects","authors":"Yangsu Xie , Xinwei Wang","doi":"10.1016/j.greenca.2023.08.004","DOIUrl":"https://doi.org/10.1016/j.greenca.2023.08.004","url":null,"abstract":"<div><p>The thermal conductivity of carbon-based nanomaterials (e.g. carbon nanotubes, graphene, graphene aerogels, and carbon fibers) is a physical property of great scientific and engineering importance. Thermal conductivity tailoring via structure engineering is widely conducted to meet the requirement of different applications. Traditionally, the thermal conductivity∼temperature relation is used to analyze the structural effect but this relation is extremely affected by effect of temperature-dependence of specific heat. In this paper, detailed review and discussions are provided on the thermal reffusivity theory to analyze the structural effects on thermal conductivity. For the first time, the thermal reffusivity-temperature trend in fact uncovers very strong structural degrading with reduced temperature for various carbon-based nanomaterials. The residual thermal reffusivity at the 0 K limit can be used to directly calculate the structure thermal domain (STD) size, a size like that determined by x-ray diffraction, but reflects phonon scattering. For amorphous carbon materials or nanomaterials that could not induce sufficient x-ray scattering, the STD size probably provides the only available physical domain size for structure analysis. Different from many isotropic and anisotropic materials, carbon-based materials (e.g. graphite, graphene, and graphene paper) have Van der Waals bonds in the c-axis direction and covalent bonds in the a-axis direction. This results in two different kinds of phonons whose specific heat, phonon velocity, and mean free path are completely different. A physical model is proposed to introduce the anisotropic specific heat and temperature concept, and to interpret the extremely long phonon mean free path despite the very low thermal conductivity in the c-axis direction. This model also can be applied to other similar anisotropic materials that feature Van der Waals and covalent bonds in different directions.</p></div>","PeriodicalId":100595,"journal":{"name":"Green Carbon","volume":"1 1","pages":"Pages 47-57"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49704788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Green CarbonPub Date : 2023-09-01DOI: 10.1016/j.greenca.2023.09.001
Vera Bikbaeva , Nikolay Nesterenko , Nuria García-Moncada , Valentin Valtchev
{"title":"Co-promoted Mo-carbide catalytic system for sustainable manufacturing of chemicals via co-processing of CO2 with ethane","authors":"Vera Bikbaeva , Nikolay Nesterenko , Nuria García-Moncada , Valentin Valtchev","doi":"10.1016/j.greenca.2023.09.001","DOIUrl":"https://doi.org/10.1016/j.greenca.2023.09.001","url":null,"abstract":"<div><p>The study reports progress in developing a molybdenum carbide-based catalyst for co-processing ethane and CO<sub>2</sub>. The cobalt promoting of molybdenum carbide improved the activity and stability of ethane transformation in the presence of CO<sub>2</sub> substantially without any impact on ethylene selectivity. The Mo-Co supported catalyst also showed interesting performance in catalyzing ethane dry reforming and that application could be a perspective further use for this system. In addition, the comprehensive analysis of mono- and bi-metallic catalysts revealed that Co-promoting prevented rapid Mo-carbide oxidation. Further, tuning operation conditions allowed to control catalyst’s selectivity and maximize CO<sub>2</sub> utilization or ethylene formation.</p></div>","PeriodicalId":100595,"journal":{"name":"Green Carbon","volume":"1 1","pages":"Pages 94-103"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49709468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Green CarbonPub Date : 2023-09-01DOI: 10.1016/j.greenca.2023.09.002
Zihe Liu , Shuobo Shi , Yuchao Ji , Kai Wang , Tianwei Tan , Jens Nielsen
{"title":"Opportunities of CO2-based biorefineries for production of fuels and chemicals","authors":"Zihe Liu , Shuobo Shi , Yuchao Ji , Kai Wang , Tianwei Tan , Jens Nielsen","doi":"10.1016/j.greenca.2023.09.002","DOIUrl":"https://doi.org/10.1016/j.greenca.2023.09.002","url":null,"abstract":"<div><p>Biorefinery production of fuels and chemicals represents an attractive route for solving current energy crisis, as well as reducing green-house gas (GHG) emissions from ships, planes, and long-haul trucks. The current biorefinery industry is under transition from the use of food (1G, 1st generation), to the use of biomass (2G, 2nd generation). Moreover, the use of atmospheric CO<sub>2</sub> (3G, 3rd generation) has caught increased attention as the possible next-generation biorefinery. Here we discuss how microorganisms can be engineered for CO<sub>2</sub>-based biorefineries to produce fuels and chemicals. We start through reviewing different metabolic pathways that can be recruited for CO<sub>2</sub> fixation, followed by different opportunities for CO<sub>2</sub> fixation, either through co-consumption with sugars or used as the sole carbon source. Key challenges and future research directions for advancing 3rd-generation biorefineries are also be discussed.</p></div>","PeriodicalId":100595,"journal":{"name":"Green Carbon","volume":"1 1","pages":"Pages 75-84"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49709466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Green CarbonPub Date : 2023-09-01DOI: 10.1016/j.greenca.2023.07.001
Jacob O. Fierer , Omar E. Tovar-Herrera , Jonathan Y. Weinstein , Amaranta Kahn , Sarah Moraïs , Itzhak Mizrahi , Edward A. Bayer
{"title":"Affinity-induced covalent protein-protein ligation via the SpyCatcher-SpyTag interaction","authors":"Jacob O. Fierer , Omar E. Tovar-Herrera , Jonathan Y. Weinstein , Amaranta Kahn , Sarah Moraïs , Itzhak Mizrahi , Edward A. Bayer","doi":"10.1016/j.greenca.2023.07.001","DOIUrl":"https://doi.org/10.1016/j.greenca.2023.07.001","url":null,"abstract":"<div><p>Production of economically viable bioethanol is potentially an environmentally and financially worthwhile endeavor. One major source for fermentable sugars is lignocellulose. However, lignocellulosic biomass is difficult to degrade, owing to its inherent structural recalcitrance. Cellulosomes are complexes of cellulases and associated polysaccharide-degrading enzymes bound to a protein scaffold that can efficiently degrade lignocellulose. Integration of the enzyme subunits into the complex depends on intermodular cohesin-dockerin interactions, which are robust but nonetheless non-covalent. The modular architecture of these complexes can be used to assemble artificial designer cellulosomes for advanced nanotechnological applications. Pretreatments that promote lignocellulose degradation involve high temperatures and acidic or alkaline conditions that could dismember designer cellulosomes, thus requiring separation of reaction steps, thereby increasing overall process cost. To overcome these challenges, we developed a means of covalently locking cohesin-dockerin interactions by integrating the chemistry of SpyCatcher-SpyTag approach to target and secure the interaction. The resultant cohesin-conjugated dockerin complex was resistant to high temperatures, SDS, and urea while high affinity and specificity of the interacting modular components were maintained. Using this approach, a covalently locked, bivalent designer cellulosome complex was produced and demonstrated to be enzymatically active on cellulosic substrates. The combination of affinity systems with SpyCatcher-SpyTag chemistry may prove of general use for improving other types of protein ligation systems and creating unconventional, biologically active, covalently locked, affinity-based molecular architectures.</p></div>","PeriodicalId":100595,"journal":{"name":"Green Carbon","volume":"1 1","pages":"Pages 33-42"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49704858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Green CarbonPub Date : 2023-09-01DOI: 10.1016/j.greenca.2023.06.001
Xuefeng Lu , Valentin Valtchev
{"title":"Green Carbon: Towards a greener world","authors":"Xuefeng Lu , Valentin Valtchev","doi":"10.1016/j.greenca.2023.06.001","DOIUrl":"https://doi.org/10.1016/j.greenca.2023.06.001","url":null,"abstract":"","PeriodicalId":100595,"journal":{"name":"Green Carbon","volume":"1 1","pages":"Page 1"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49704714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}