Solid electrochemical mass spectrometry (SEMS) for investigation of supported metal catalysts under high vacuum

Abstract

A new experimental set-up, coupling electrochemistry and mass spectroscopic techniques, for the investigation of a solid electrochemical cell under high vacuum conditions (HV) is presented. Two configurations are realized allowing the investigation of both the electrochemical and electrocatalytical behavior of a thin Pt layer on yttria stabilized zirconia (YSZ). We can readily select the atmosphere down to 10 -6 Pa partial pressure and determine the response of the system in less than 1 s. Under HV conditions, YSZ appears electrochemically active and we have identified, in the cathodic potential domain, the reduction/oxidation process of zirconia and in the anodic domain, the platinum oxidation/reduction and the oxygen evolution reactions. In a catalytic active gas mixture, despite the Faradaic enhancement of the CO oxidation observed over Pt/YSZ during an anodic polarization, an intriguing sustainable enhanced Pt/YSZ catalyst activity is achieved after current interruption.

Electrochemical promotion of CO combustion over Pt/YSZ under high vacuum conditions

“…Electrochemical measurement were carried out under high vacuum (HV) conditions with a background pressure of 10 −6 Pa by solid electrochemical mass spectroscopy (EMS) using a setup described in detail elsewhere [10]. This electrochemical technique involves the imposition of an electrochemical perturbation (Autolab, Metrohm, and PGSTAT30) to the system while monitoring directly by mass spectrometry (QMS, Pfeiffer, Prisma200) the formation of products released into the gas phase.…”

“…In order to shed more light on these processes, a high vacuum (HV) setup was built to perform the electrochemical investigation over Pt/YSZ at 400 • C as described recently [10]. Under anodic polarization, oxygen evolution reactions are identified.…”

Investigation of the Pt/YSZ interface at low oxygen partial pressure by solid electrochemical mass spectroscopy under high vacuum conditions

“…Electrochemical investigations are performed under high vacuum (HV) conditions (10 -6 Pa) at 400°C by solid electrochemical mass spectroscopy (SEMS) using a setup described in detail elsewhere [7]. This new electrochemical technique involves the imposition of an electrochemical perturbation (PGSTAT30, EcoChemie) to the system while monitoring directly by mass spectrometry (QMS, Pfeiffer, Prisma200) the formation of electrochemical products (in the case of this paper O 2(g) ), released into the gas phase.…”

“…In this technique, described in detail in a previous paper [7], an electrochemical perturbation is imposed to the Pt/YSZ interface. This perturbation can lead to the formation of O 2 (g) which is analyzed online by mass spectrometry.…”

Quantifying electrochemical promotion of induced bipolar Pt particles supported on YSZ

“…The experimental setup used in this experiment has been described elsewhere [11] and only details specific to this investigation are given here.…”