Velocity-selected spatial map ion imaging spectrometer for direct imaging of near-surface catalytic activity

Article Chemistry, Physical

Gas-Phase Hydrogen-Atom Measurement above Catalytic and Noncatalytic Materials during Ethane Dehydrogenation

Scott A. Steinmetz et al.

Summary: The role of solid surface in initiating gas-phase reactions, particularly the interaction between hydrogen atoms and surface sites, is still not well understood. This study presents the first measurements of hydrogen concentrations by laser-induced fluorescence in the gas-phase above catalytic and noncatalytic surfaces. The results show that hydrogen concentrations are highest above inert quartz surfaces compared to stainless steel and a platinum-based catalyst, and concentrations above the catalyst decrease rapidly with time on stream. These findings support the previously reported differences in bulk ethane dehydrogenation reactivity of these materials, suggesting hydrogen may serve as a good indicator for dehydrogenation activity.

JOURNAL OF PHYSICAL CHEMISTRY C (2022)

Add to Collection

Article Chemistry, Physical

Visualizing the Gas Diffusion Induced Ignition of a Catalytic Reaction

Sebastian Pfaff et al.

Summary: Many surface science experiments in the field of heterogeneous catalysis are now conducted under more realistic conditions, i.e., at higher pressures. Under these pressures, localized gas conditions are formed within the reactor. Understanding the interaction between these gas conditions and the catalyst surface at relevant time and space scales is crucial. To address this, a combination of techniques is used to analyze the composition of gas and surface with sufficient temporal and spatial resolution. By conducting an operando experiment that combines these techniques, it is demonstrated that the spatial evolution of catalytic ignition over Pd(100) during CO oxidation at higher pressures is driven by localized gas conditions, highlighting the importance of 2D gas-phase measurements when studying model catalysts under high-pressure conditions.

ACS CATALYSIS (2022)

Add to Collection

Article Multidisciplinary Sciences

Periodic structural changes in Pd nanoparticles during oscillatory CO oxidation reaction

Tanmay Ghosh et al.

Summary: Nanoparticle catalysts are widely used in energy systems and chemical production. This study provides atomic-scale insights into the dynamic surface properties of nanoparticles under reactive conditions, which play a crucial role in designing high-performance catalysts.

NATURE COMMUNICATIONS (2022)

Add to Collection

Article Chemistry, Physical

Near-Surface Imaging of the Multicomponent Gas Phase above a Silver Catalyst during Partial Oxidation of Methanol

Bo Zhou et al.

Summary: Operando techniques are increasingly used to study fundamental chemistry in heterogeneous catalysis, addressing the pressure gap between ultrahigh vacuum studies and practical operating pressures. These techniques enable visualization and measurement of gas-phase species and temperature distributions, providing valuable insights into catalytic mechanisms. The combination of different techniques offers a detailed picture of the coupling between the gas phase and surface in heterogeneous catalysis for enhanced understanding of catalytic processes.

ACS CATALYSIS (2021)

Add to Collection

Article Chemistry, Physical

Near-Surface Gas-Phase Methoxymethanol Is Generated by Methanol Oxidation over Pd-Based Catalysts

Sadi M. Gurses et al.

Summary: The study identified methoxymethanol as a critical intermediate in the catalytic oxidative conversion of methanol, and investigated the temperature and reactant feed ratio dependences of its generation. These findings are important for the future development of catalysts and microkinetic models.

JOURNAL OF PHYSICAL CHEMISTRY LETTERS (2021)

Add to Collection

Article Instruments & Instrumentation