A transient flow reactor for rapid gas switching at atmospheric pressure

Abstract

Herein, we present a design for a transient flow reactor system with high detection sensitivity and minimal dead volume, such that it is capable of sub-second switching of the gas stream flowing through a catalytic bed. We demonstrate the reactor's capabilities for step transient, pulse, and stream oscillation experiments using the model system of CO oxidation over Pd catalysts, and we find that we are able to precisely model step transients for CO oxidation using a pseudo-homogenous-packed bed reactor model. The design principles leading to minimal gas hold-up time and increased sensitivity that are described in this paper can be implemented into existing flow reactor designs with minimal cost, providing a readily accessible alternative to the existing transient instrumentation.

A well-defined supported Pt nanoparticle catalyst for heterogeneous catalytic surface science

“…The DRIFTS reaction chambers were connected to an external gas handling system consisting of a set of parallel mass flow controllers that is described in our previous publication and in section 2.5. 40…”

“…The CO and O 2 chemisorption experiments were performed using a home-built rapid transient flow reactor that has been described previously, 40 but is summarised here. Two parallel gas streams are generated using 4 mass flow controllers per stream (8 total, Alicat Scientific) which are fed into a two-position four-port microelectric valve (VICI) where one line is sent into the packed bed reactor, and the other is sent through a bypass line.…”

In Situ Analysis of Gas Dependent Redistribution Kinetics in Bimetallic Au-Pd Nanoparticles

“…The gas flow through the DRIFTS reactor was controlled by a rapid switching gas handling system. 52 The catalyst sample was prepared by pressing and sieving between 304 stainless-steel meshes (50 × 50 mesh and 70 × 70 mesh). The DRIFTS reactor was loaded with approximately 135 mg of 46 grit SiC, an inert support with high thermal conductivity, followed by approximately 15 mg of the prepared AuPd/SiO2 catalyst.…”

Interrogating site dependent kinetics over SiO2-supported Pt nanoparticles

“…The N 2 adsorption isotherm at 77 K of the SiO 2 support was collected by surface characterisation analyser (3Flex, Micromeritics). The steady-state flow catalytic activity was measured in a home-built ambient pressure flow reactor that has been previously described 77 with all gas mixtures reported balanced in Ar (See Supplementary IV).…”