Rapid scan FTIR reveals propane (am)oxidation mechanisms over vanadium based catalysts

Light hydrocarbon conversion to acrylonitrile and acetonitrile - a review

Nitriles, particularly acrylonitrile and acetonitrile, are versatile chemicals that are used in various fields, such as polymer synthesis and pharmaceutical production. For a long time, acrylonitrile has been produced via propylene ammoxidation with acetonitrile as a byproduct. The depletion of crude reservoirs and the production of unconventional hydrocarbon resources (e.g., shale gas) renders light alkanes (including propane, ethane, and methane) to be potential feedstocks in the syntheses of acrylonitrile and acetonitrile. In this review, the processes of transforming light hydrocarbons to nitriles are surveyed, the developments in nitrile synthesis from alkanes are discussed, and the existing challenges and plausible solutions are addressed.

Investigation of vanadia-alumina catalysts with solid-state NMR spectroscopy and DFT

In this work, isolated surface sites of vanadium oxide on the alumina surface were modeled and compared to experimental data obtained with ⁵¹V Solid-State Nuclear Magnetic Resonance (SSNMR) spectroscopy. The geometry of the centers on the (100), (110), and (111) planes of the spinel structure and (010) monoclinic alumina was modeled using density functional theory (DFT); their ⁵¹V NMR parameters were calculated using the Gauge-Including Projector Augmented Wave (GIPAW) method. The comparison of the simulated theoretical spectra with the experimental ones made it possible to find the sites that are likely present on the surface of real catalysts. The minimum energy pathways of propane oxidative dehydrogenation to propene were calculated for the dioxovanadium site in order to estimate its activity.

Operando Fourier-transform infrared-mass spectrometry reactor cell setup for heterogeneous catalysis with glovebox transfer process to surface-chemical characterization

We describe a new type of operando Fourier transform infrared (FTIR)-mass spectrometry setup for surface-chemical and reactivity characterization of heterogeneous catalysts. On the basis of a sophisticated all-quartz FTIR reactor cell, capable of operating between room temperature and 1000 °C in reactive gas atmospheres, the setup offers a unique opportunity to simultaneously collect and accordingly correlate FTIR surface-chemical adsorption data of the active catalyst state and FTIR gas phase data with complementary reactivity data obtained via mass spectrometry in situ. The full set of catalytic operation modes (recirculating static and flow reactor conditions) is accessible and can be complemented with a variety of temperature-programmed reaction modes or thermal desorption. Due to the unique transfer process involving a home-built portable glovebox to avoid air exposure, a variety of complementary quasi in situ characterization methods for the pre- and post-reaction catalyst states become accessible. We exemplify the capabilities for additional x-ray photoelectron spectroscopy characterization of surface-chemical states, highlighting the unique strength of combining adsorption, electronic structure, and reactivity data to gain detailed insight into the reactive state of a Cu/ZrO₂ heterogeneous catalyst during methanol steam reforming operation.

Surface phase structures responsible for the activity and deactivation of the fcc MoC (111)-Mo surface in steam reforming: a systematic kinetic and thermodynamic investigation

Multiscale investigation on MoC surface phase evolution to clarify surface structures responsible for reactivity and deactivation in steam reforming.