title: Interplay between Reaction and Phase Behaviour in Carbon Dioxide Hydrogenation to Methanol.
abstract: Condensation promotes CO2hydrogenation to CH3OH beyond equilibrium through in situ product separation. Although primordial for catalyst and reactor design, triggering conditions as well as the impact on sub-equilibrium reaction behaviour remain unclear. Herein we used an in-house designed micro-view-cell to gain chemical and physical insights into reaction and phase behaviour under high-pressure conditions over a commercial Cu/ZnO/Al2O3catalyst. Raman microscopy and video monitoring, combined with online gas chromatography analysis, allowed the complete characterisation of the reaction bulk up to 450 bar (1 bar=0.1 MPa) and 350 °C. Dew points of typical effluent streams related to a parametric study suggest that the improving reaction performance and reverting selectivities observed from 230 °C strongly correlate with (i) a regime transition from kinetic to thermodynamic, and (ii) a phase transition from a single supercritical to a biphasic reaction mixture. Our results advance a rationale behind transitioning CH3OH selectivities for an improved understanding of CO2hydrogenation under high pressure.
authors.affiliation: Institute of Process Engineering, ETH Zürich, Sonneggstrasse 3, 8092, Zürich, Switzerland.
authors.forename: Helena
authors.identifier: 0000-0001-5183-2446
authors.initials: H
authors.lastname: Reymond
authors.affiliation: Institute of Process Engineering, ETH Zürich, Sonneggstrasse 3, 8092, Zürich, Switzerland.
authors.forename: Victor
authors.initials: V
authors.lastname: Amado-Blanco
authors.affiliation: Institute of Process Engineering, ETH Zürich, Sonneggstrasse 3, 8092, Zürich, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lauper
authors.affiliation: Institute of Process Engineering, ETH Zürich, Sonneggstrasse 3, 8092, Zürich, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Rudolf von Rohr
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D006865:Hydrogenation; D000432:Methanol / Q000737:chemistry*; D044366:Transition Temperature; D015032:Zinc / Q000737:chemistry
chemical_list: D002245:Carbon Dioxide; D003300:Copper; D015032:Zinc; D000537:Aluminum Oxide; D000432:Methanol
keywords: carbon dioxide; heterogeneous catalysis; high pressure; hydrogenation; raman spectroscopy