First Author: Wang Kangzhou
Corresponding authors (or co-corresponding authors): Tsubaki Fan Li, Tadashi Nakaji-Hirabayashi, Wang Yang
Correspondence Units: Ningxia University, National University of Toyama, Japan, China University of Petroleum (East China), Toyo Tire Co., Ltd
**doi：10.1016/j.chempr.2024.01.004
Quick facts about the full article
In this paper, the important prospects, process routes, development status and important challenges of the key reactions involved in the synthesis of butadiene rubber using CO2 as raw material are described. This paper focuses on the research progress of Tsubaki Lab in recent years in the design of integrated catalytic system design and development of efficient catalyst for "CO2 to ethanol-ethanol to butadiene-butadiene polymerization to butadiene rubber". In terms of industrial application, the recent teamwork to develop the original technology of CO2 synthetic butadiene rubber and the expansion and application of zero-carbon negative butadiene rubber in tire manufacturing were introduced.
Background
Butadiene rubber is one of the most consumed synthetic rubber in the world, and its traditional production process is overly dependent on fossil raw materials such as **, which has disadvantages such as high carbon emissions. In the face of the contradiction between rising demand and carbon reduction, it is urgent to develop new technologies for the synthesis of zero-carbon or even carbon-negative butadiene rubber. The synthesis of butadiene rubber using CO2 as raw material through multi-step reaction process is expected to open up a new route for the synthesis of non-fossil raw material butadiene rubber, and at the same time realize the resource utilization of greenhouse gas CO2, which is an innovative technology that is fully in line with today's concept of green and sustainable development.
Highlights of this article:
1) The important prospects and challenges of synthesizing butadiene rubber using CO2 as raw material were systematically expounded.
2) The progress of Tsubaki Lab in the development of integrated reaction systems and industrial application expansion was highlighted. (3) The purpose of this work is to inspire new technologies for CO2 resource utilization and new routes for the synthesis of high-value chemicals.
Parsing
The process route of butadiene rubber synthesis using CO2 as raw material proposed by Tsubaki Lab includes three important reactions: CO2 hydrogenation to ethanol, ethanol to butadiene, and butadiene polymerization to butadiene rubber.
Figure 1Schematic diagram of a representative catalyst and reaction mechanism for CO2 to butadiene rubber
(1) CO2 hydrogenation to ethanol
Fe-based, Cu-based and PD-based catalysts are commonly used catalysts for CO2 hydrogenation to ethanol. The typical electron buffering effect of carbon-supported Fe-based catalysts optimizes the adsorption strength and behavior of key reaction intermediates and stimulates ethanol synthesis performance (angew chem. int. ed. 2023, e202311786）；Fe&Cu coupled cascade catalyst to improve the ethanol selectivity of the target product by optimizing the coverage of oxygen-containing intermediates at the catalyst interface (ACS catal 2021, 11, 11742-11753）；TiO2 surface-OH can optimize the reaction network of Fe&Rh-based catalyst CO2 hydrogenation to ethanol (Chem.). sci. 2019, 10, 3161-3167）；The dual-PD atom reservoir concept catalyst can stabilize the two-PD atom through water molecules, thereby improving the stability of CO2 hydrogenation to ethanol (ACS Catal 2023, 13, 7110-7121）。Although a variety of rational design cases of catalysts have been reported, the synthesis efficiency of ethanol still needs to be improved, and there is still a lack of high-resolution characterization techniques to observe and capture the key reaction intermediates of ethanol synthesis under real reaction conditions.
(2) Direct conversion of ethanol to butadiene
In order to solve the problems of low selectivity and poor stability of ethanol direct conversion to butadiene catalyst and the inhibition of acid site activity in aldol condensation reaction by water vapor. By constructing isolated Zr-O-Si bonds, optimizing the adsorption-desorption behavior of important intermediates at the active site and the structure of the catalyst, the butadiene selectivity and catalyst stability were improved (APPL.). catal. b: environ. 2022, 301, 120822, acs sustainable chem. eng. 2021, 9, 10569-10578）；By optimizing the acid-base properties and coordination structure of the catalyst, the competitive adsorption of key intermediates and water molecules at the active site was regulated, and the ethanol conversion rate and butadiene selectivity were improved by optimizing the acid-base properties and coordination structure of the catalyst eng. j. 2024, 479, 147780，appl. surf. sci.2022, 602, 154299), butadiene yield was significantly better than that of the reported catalytic system.
(3) Butadiene polymerization to butadiene rubber
The content ratio of 1,4-cis, 1,4-trans and 1,2-vinyl units on the polymer chain determines the physical properties of butadiene rubber, and the proportion of 1,4-cis can be adjusted by changing the polymerization method, such as Ziegler-Natta catalyst is suitable for the synthesis of high 1,4-cis butadiene rubber, while alkyl lithium catalyst is suitable for the synthesis of low 1,4-cis butadiene rubber. Toyo Tire Co., Ltd. uses a self-developed polymerization catalyst and catalytic system to polymerize butadiene into butadiene rubber, thus opening up the entire process from CO2 to butadiene rubber.
(4) Industrial application expansion
May 9, 2023National University of Toyama, JapanAt a joint press conference in Tokyo, the University of Tokyo and Toyo Tire Co., Ltd. announced the successful development of a new technology for the synthesis of butadiene rubber using CO2 as a raw material, and the butadiene rubber produced based on this technology is being used in the practical production of racing tires at Toyo Tire Co., Ltd., and the tires produced will be assembled in racing cars to participate in the Paris-Dakar Desert Cross-Country Rally and the 24 Hours of Neuburglin Endurance Challenge in Germany to provide important information into the mass production technology. The sustainable circular technology is expected to be commercially available by the end of 2029.
Figure 2At the press conference on CO2 butadiene rubber, Professor Tsubaki (left) and Ichiro Shima (right), Executive Director (*Toyo Tire Co., Ltd.).
Summary and outlook
CO2 conversion to butadiene rubber requires hydrogen**, and water electrolysis is a simple, sustainable strategy for continuous hydrogen production and a zero-carbon process. At present, water electrolysis accounts for 4% of global hydrogen production, and reducing the cost of hydrogen production from water electrolysis is of great significance for the development of CO2 hydrogenation and the eventual realization of the vision of carbon neutrality.
About the Author:
Corresponding Author:
Tsubaki, NoritatsuNational University of Toyama, JapanChair Professor of Catalytic Energy and Chemical Engineering, Faculty of Engineering, Founding Director of the Low Carbon Technology Center of the University of Toyama, graduated from the Department of Chemical Physics, University of Science and Technology of China in 1987, received a master's degree in Chemical and Energy Engineering from the University of Tokyo in 1992, received a Ph.D. in the Department of Applied Chemistry from the University of Tokyo in 1995, served as a teaching assistant, lecturer, and associate professor at the University of Tokyo from 1995 to 2000, and served as a chair professor at the University of Toyama since 2001, and was awarded the 2006 Japan Society for the Promotion of Science Award, and the 2017 Japan Energy Society Society Award (Lifetime Achievement Award). In 2019, he was elected as an academician of the Japanese Academy of Engineering, in 2021, he was awarded the International Cooperation Award of the China Petroleum and Chemical Industry Federation, and in 2022, he was awarded the Science and Technology Award of the Minister of Liberal Arts and Science of Japan in 2022. He has published more than 500 academic papers and more than 100 patents.
Wang YangChina University of Petroleum (East China).Associate Professor, School of New Energy. In 2019, he received his Ph.D. degree from the National University of Toyama, JapanTsubaki, Academician Noritatsu）。His research interests include the development of carbon-based catalytic materials and their applications for carbon-one molecular catalytic conversion, such as Fischer-Tropsch synthesis, CH4 dry reforming, CO2 conversion, etc. As the first corresponding author in ACC chem. res.、chem、angew. chem. int. ed.He has published more than 20 articles in other publications, presided over the sub-projects of the National Key R&D Program, the National Natural Science Youth Project, and the horizontal of PetroChina Shandong Energy Group Enterprises, and served as a youth editorial board member of Green Carbon Journal.
First Author:
Wang KangzhouNingxia UniversityAssociate Professor, School of Materials and New Energy. In 2022, he received his Ph.D. degree from the National University of Toyama, Japan (supervised by Academician Tsubaki, Noritatsu). His research interests include the preparation of nanoporous catalytic materials and their applications in the conversion of carbon resources. As the first corresponding author in chem, appl catal. b: environ.、chem. eng. j.and other journals published more than 20 articles; As the project leader, he undertook 4 provincial, ministerial and enterprise horizontal projects; He won the first prize of invention, entrepreneurship and innovation of the China Association of Inventions, the outstanding graduate of the doctoral program of the Ministry of Science and Engineering, and the doctoral program scholarship of the Ministry of Education, Culture, Sports, Science and Technology of Japan. He served as a young editorial board member of Chinese Journal of Structure Chemistry and Advanced Powder Materials.