EMIL

High-pressure reactor

A new reactor apparatus compatible with high temperature and pressure catalytic processes (e.g., hydrogenation reactions) is attached to the UHV-backbone in EMIL. The connection of the chamber to the UHV-backbone allows for sample preparation, reaction, and characterization, to be carried out at controlled contamination conditions without exposing the sample to glovebox or ambient environments. The tools connected to the UHV backbone can be utilized to synthesize thin film model catalysts of precise structure and chemical composition that can mimic the “real” catalytic materials. The samples can be exposed to reaction conditions that are industrially relevant, while advanced characterization can be applied before and after reactions. For that purpose, either lab-scale (e.g. XPS) or synchrotron-based techniques (HAXPES and XAS with soft and tender x-rays at the SISSY I endstation) can be used. For attaining high pressure reaction conditions and for facile transfer of the sample to the UHV-backbone, the reactor is consisted of two cups that enclose a low reactor volume (~150 mL) which can be filled with gases and pumped down in short times, while the chamber surrounding the reactor remains in vacuum conditions (see Figure 1).

Figure 1: Scheme (full view on the left and cut view on the right) of the high-pressure rector cell attached to the UHV-backbone at EMIL

The reactor can be heated up to 650 °C by both IR and ceramic heaters and can operate at total pressure up to 20 bar both in static and flow mode. The sample holder can accommodate thin film or powder samples, and gases are introduced in the reactor via mass flow controllers (MFCs). Available gas lines at EMIL are among others low pressure H₂, N₂, Ar, O₂ (up to 6 bar) and high pressure H₂, CO, CO₂, and N₂ (up to 20bar), thus is possible to approach industrial conditions of reactions such as Fischer-Tropsch or CO₂ hydrogenation for methanol production. The outlet of the reactor is connected to gas analytic devices (e.g., mass spectrometer and/or gas-chromatograph) for assessing the catalytic performance. Unattended operation and remote control of the whole setup render running long-term experiments feasible, while the system is equipped with CO sensors and other safety measures that will automatically end operation in case of emergency. The aim of the high-pressure reactor is to bridge the gap between surface science techniques that are generally carried out in UHV conditions with realistic reaction conditions for deriving further knowledge about the mechanism of catalytic reactions.