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Item type:Publication, Access status: with files , Investigations on the role of support and synthesis procedure for the Rux–Cuy/CNT‐catalysed hydrogenolysis of glycerol to 1,2‐propanediol(Wiley, 2026-07-14); ; ; Tailoring support effects plays an important role for controlling activity and selectivity in heterogeneously catalyzed gas–liquid reactions. Sophisticated carbon supports like single‐ and multiwall carbon nanotubes (CNTs) as well as in house produced Globugraphite were used for the synthesis of bimetallic Ru–Cu catalysts, which were tested in a multibatch reactor setup for the chemical hydrogenolysis of glycerol to 1,2‐propanediol (1,2‐PDO) in aqueous solution. In‐depth characterization using multiple tools like inductively coupled plasma optical emission spectrometry, CHNS‐O analysis, N₂‐physisorption, scanning electron microscopy, transmission electron microscopy, energy‐dispersive X‐ray spectroscopy, powder X‐ray diffraction, H₂‐temperature programmed reduction, laser diffraction, and point of zero charge measurements revealed the dominating effects that the various carbon supports exert on the catalytic performance. The best‐performing catalyst synthesized by wetness impregnation consisted of Ru–Cu₃ nanoparticles (NPs) from mixed RuCl₃ and Cu(NO₃)₂ precursors dispersed on multiwall CNT Baytubes with a productivity of p = 12.74 g₁,₂‐PDO gactive metal ⁻¹ h⁻¹ . Its superior activity combined with high 1,2‐PDO selectivity (S= 75%) can be explained both by the nature of the highly dispersed Ru and Cu NPs showing the lowest reduction peak temperature on entangled tubes of CNT agglomerates demonstrating a high mesopore volume for optimal reactant accessibility and the highest specific surface area of all investigated materials. This lays the foundation for implementing this highly active and selective catalyst in a future SMART reactor for glycerol valorisation.Publicationtype: Journal Article58 43 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Glycerol hydrogenolysis goes SMART - separating reaction steps as a key for tailoring selectivity and reaction control(American Chemical Society (ACS), 2026-05-27); ; ; ; The next generation of flexible, efficient, and robust chemical processes requires adaptive, resilient, and autonomous process systems that drive the transition from fossil to renewable feedstocks as one of the central challenges in building climate-neutral and sustainable chemical value chains. One central element will be the next generation of reactors that are SMART -Sustainable, Multipurpose, Autonomous, Resilient, and Transferable- merging process engineering with materials science, analytics, electronics, and data science. Herein, the chemical hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO) was used as a case study for tailoring selectivity and reaction control by coupling modeling with experimental approaches for process control, demonstrating adaptive reactor behavior. In detail, the reaction was split into a high-temperature step for the endothermic glycerol dehydration under an inert atmosphere and a consecutive low-temperature step under a hydrogen atmosphere, optimizing the reaction conditions for both reactions and deducing individual kinetic parameters by a graphical analysis of one-factor-at-a-time variations and a global nonlinear regression for the temporal concentration data. The results yield a reaction order of around 0.27 for glycerol with an activation energy of 43 kJ mol−1 for the dehydration step as well as reaction orders of zero for acetol and around 2.15 for hydrogen at an activation energy of 57 kJ mol−1 for the hydrogenation step. The simulated concentration profiles highlight the good agreement between the model and the experimental data. This allows for the implementation of the two-step reaction in a SMART reactor, strengthening the vision of a future generation of autonomous, resilient, and transferable process systems.Publicationtype: Journal Article58 53 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Boosting the chemical hydrogenolysis of glycerol to 1,2-propanediol to almost perfect selectivity using a multifunctional Ru–Cu carbon-nanotube-supported catalyst(American Chemical Society (ACS), 2026-04-03); ; ; Chemical hydrogenolysis of glycerol to propanediols is a promising strategy for biomass valorization. However, the demanding reaction conditions and deviating requirements for the individual reaction steps cause significant challenges to date. Herein, a kinetic study for the chemical hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO) as well as an optimized reaction procedure using a multifunctional Ru–Cu/CNT catalyst is presented. In detail, it was shown that the glycerol hydrogenolysis reaction is neither influenced by mass nor heat transfer limitations under the applied reaction conditions. Consequently, the following kinetic parameters could be deduced both by experimental determination as well as kinetic modeling: n (glycerol) = 1.1, n (H2) = 0.12 up to 25 bar (kinetic regime), and an activation energy of 150 kJ mol–1 for the desired 1,2-PDO pathway, as well as n (glycerol) = n (H2) = 0 for the undesired ethylene glycol pathway at an activation energy of around 65 kJ mol–1. Moreover, separating glycerol hydrogenolysis into two steps, initial glycerol dehydration to acetol under a nitrogen atmosphere at a high temperature of 220 °C, followed by acetol hydrogenation to 1,2-PDO under a hydrogen atmosphere at a low temperature of 145 °C using the same Ru–Cu/CNT catalyst, can lead to higher overall yields and almost perfect selectivity for 1,2-PDO. This could be verified in a separate experiment showing acetol selectivity of >99% for the first and 1,2-PDO selectivity of >99% for the second step without observable ethylene glycol production. Compared to the combined reaction under standard hydrogenolysis conditions of 50 bar H2 and 220 °C, almost perfect 1,2-PDO selectivity could be achieved, showing great potential for the separate approach. Moreover, a kinetic model of the glycerol hydrogenolysis based on the experimentally derived reaction rates confirms that the models reliably reproduce the observed reaction behavior with respect to the observed kinetic parameters.Publicationtype: Journal Article96 56 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Multifunctional carbon‐nanotube supported catalyst for efficient glycerol hydrogenolysis to 1,2‐propanediol(Wiley, 2026-03); ; Multiwall carbon nanotube (NC7000) supported mono-, bi-, and trimetallic catalysts were synthesized and tested in a multi- batch reactor setup supported by data-driven modeling for the chemical hydrogenolysis of glycerol to 1,2-Propanediol (1,2-PDO) at 220◦C under 30 bar hydrogen pressure in aqueous solution. ICP-OES, N2 -physisorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDX), powder x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) were used to investigate the physico-chemical properties of the synthesized catalysts. Interesting structure-activity-selectivity correlations could be deduced from the different metal ratios and combinations. While Ru was by far the most active monometallic species ( X = 100%), followed by Pt ( X = 80%) and Ir ( X = 65%), it suffered from a very low 1,2-PDO selectivity ( S < 10%). Combining Ru with the more selective transition-metals RuX2 ( X = Fe, Co, or Ni) maintained the high activity ( X > 95%) but only moderately increased 1,2-PDO selectivity ( S = 20%–30%). Interestingly, combining Ru with Cu in a bimetallic RuCu2 catalyst slightly decreased activity ( X = 81%) but drastically improved 1,2-PDO selectivity ( S = 58%). Moreover, a trimetallic combination of RuMCu2 (M = Pt, Pd, Ir) did not further increase activity ( X = 50%–70%) but could push 1,2-PDO selectivity up to 79% for the trimetallic RuIrCu2 catalyst. Most prominently, a final metal ratio variation for the RuCux catalyst was derived with the help of the data-driven models producing the most promising RuCu3 /NC7000) catalyst combining both high activity ( X = 78%) with a very high 1,2-PDO selectivity ( S = 79%) resulting in the highest 1,2-PDO yield of 58% in a nearly closed carbon balance ( C > 95%). This lays the foundation for implementing this highly active and selective catalyst in a future SMART reactor for glycerol valorization.Publicationtype: Journal Article88 81