Integrating Hydroformylations with Methanol-to-Syngas Reforming

Organic Chemistry Energy Chemistry Chemistry Catalysis
methanol hydroformylation syngas renewable energy bimetallic catalysis

Academic Background

With the global demand for sustainable development on the rise, the chemical industry is facing an urgent challenge to transition from fossil fuels to renewable resources. Currently, the carbon skeleton of the vast majority of synthetic chemical products is derived from non-renewable fossil fuels, which not only exacerbates carbon emissions but also makes the chemical industry one of the main consumers of fossil resources. In order to achieve carbon neutrality, the chemical industry needs to seek new sources of carbon, especially green chemical approaches that utilize carbon dioxide (CO₂) as a raw material. Methanol, as a potential sustainable chemical platform, has gained widespread attention in recent years due to its ease of production from CO₂ and green hydrogen. Methanol can be used not only as a fuel, but also as an intermediate in chemical synthesis, and can be further converted into other high-value-added chemicals.

However, integrating methanol into existing chemical production chains still faces multiple challenges. One of the key issues is how to efficiently convert methanol into syngas (a mixture of CO and H₂) for further use in the hydroformylation of olefins. Hydroformylation is one of the most important reactions in the chemical industry, used to convert olefins into aldehydes, which are widely used in the production of plastics, pharmaceuticals, and fine chemicals. Currently, syngas is mainly obtained through coal gasification or natural gas reforming, both of which rely on fossil fuels. Therefore, developing a methanol-based method for syngas generation and combining it with hydroformylation has important scientific and practical value.

Source of the Paper

This paper was co-authored by Andreas Bonde, Joakim Bøgelund Jakobsen, Alexander Ahrens, Weiheng Huang, Ralf Jackstell, Matthias Beller, and Troels Skrydstrup. The authors are from the Carbon Dioxide Activation Center (CADIAC) and the Novo Nordisk Foundation CO₂ Research Center (CORC) at Aarhus University, Denmark, and the Leibniz Institute for Catalysis in Germany. The paper was published in the journal Chem on March 13, 2025, titled “Integrating Hydroformylations with Methanol-to-Syngas Reforming.”

Research Process and Results

1. Research Objective and Methods

The aim of this study was to develop a dual-catalysis system that converts methanol into syngas, which is then used for the hydroformylation of olefins. The research team designed a two-reactor system, in which methanol undergoes dehydrogenation and olefins undergo hydroformylation, respectively. Under the action of a ruthenium (Ru) catalyst, methanol undergoes acceptorless dehydrogenation to generate CO and H₂, which is then used in the reaction with olefins under a rhodium (Rh) catalyst to produce aldehydes.

2. Optimization of Methanol Dehydrogenation

The research team first optimized the methanol dehydrogenation reaction. Using a ruthenium catalyst (Ru-Macho), methanol can be efficiently converted to CO and H₂ at 150°C. To match the conditions for hydroformylation, the team introduced toluene as a solvent into the reaction system and adjusted the concentration of methanol. Experiments showed that when the concentration of methanol was 1.5 equivalents, the reaction efficiency was the highest and the generated syngas had a ratio of H₂:CO = 2:1, which matches the optimal conditions for the hydroformylation reaction.

3. Development of the Dual-Catalysis System

After optimizing the methanol dehydrogenation, the research team designed a two-reactor system combining methanol dehydrogenation and hydroformylation. The methanol dehydrogenation reaction is conducted in the first reactor, and the generated syngas is transferred via a gas transfer system to the second reactor, where it reacts with olefins under a rhodium catalyst for hydroformylation. Experiments showed that this system can efficiently convert a variety of olefins into the corresponding aldehydes, and with high linear selectivity.

4. Substrate Scope and Extended Applications

To verify the general applicability of this dual-catalysis system, the research team tested a variety of olefinic substrates, including styrene derivatives, aliphatic olefins, as well as natural products and drug precursors. Experimental results showed that this system can efficiently convert these olefins into the corresponding aldehydes with good functional group compatibility. In addition, the team also attempted to use isotopically labeled methanol (such as methanol-13C and methanol-d4) as the syngas source and successfully synthesized isotopically labeled aldehydes, providing a new tool for pharmaceutical metabolism studies.

5. Application of Industrial-Grade Green Methanol

To further verify the industrial application potential of this system, the research team used industrial-grade green methanol (Vulcanol) as the syngas source. Vulcanol is methanol produced from CO₂ and green hydrogen, and is entirely based on renewable resources. Experiments showed that using Vulcanol as the syngas source, the system can still efficiently convert olefins into aldehydes with reaction efficiency comparable to laboratory-grade methanol. In addition, the team successfully scaled up the dual-catalysis system to the gram scale, further demonstrating its feasibility for industrial applications.

Conclusions and Significance

This study successfully developed a methanol-based dual-catalysis system that converts methanol into syngas and uses it for the hydroformylation of olefins. The system can efficiently convert a wide range of olefins into aldehydes, and also shows good functional group tolerance and linear selectivity. Furthermore, by using industrial-grade green methanol, the system demonstrates great potential for sustainable chemical industry applications. This work provides a feasible pathway for the chemical industry’s transition from fossil fuels to renewable resources and offers a new approach for future green chemical synthesis.

Research Highlights

  1. Green Methanol as a Syngas Source: This study is the first to use green methanol as a syngas source for the hydroformylation of olefins, demonstrating its potential for applications in sustainable chemical industry.
  2. Design of a Dual-Catalysis System: By designing a two-reactor system, the team successfully integrated methanol dehydrogenation with hydroformylation, achieving efficient and selective synthesis of aldehydes.
  3. Application of Isotope Labeling: The team successfully synthesized isotopically labeled aldehydes, providing a new tool for pharmaceutical metabolism research.
  4. Industrial-Scale Experiments: With the use of industrial-grade green methanol and gram-scale experiments, the team demonstrated the industrial applicability of this system.

Other Valuable Information

This study also explored the possibility of using intermediates of methanol dehydrogenation (such as formaldehyde and methyl formate) as alternative syngas sources. The experiments showed that although these intermediates can also generate syngas, their reaction efficiency is not as high as that of methanol. This finding further emphasizes the advantage of methanol as a syngas source.

This research provides important scientific evidence and technical support for the green transformation of the chemical industry, showcasing the great potential of methanol as a sustainable chemical platform.