New ambient pressure photoemission endstation at Advanced Light Source beamline 9.3.2

Abstract

During the past decade, the application of ambient pressure photoemission spectroscopy (APPES) has been recognized as an important in situ tool to study environmental and materials science, energy related science, and many other fields. Several APPES endstations are currently under planning or development at the USA and international light sources, which will lead to a rapid expansion of this technique. The present work describes the design and performance of a new APPES instrument at the Advanced Light Source beamline 9.3.2 at Lawrence Berkeley National Laboratory. This new instrument, Scienta R4000 HiPP, is a result of collaboration between Advanced Light Source and its industrial partner VG-Scienta. The R4000 HiPP provides superior electron transmission as well as spectromicroscopy modes with 16 microm spatial resolution in one dimension and angle-resolved modes with simulated 0.5 degrees angular resolution at 24 degrees acceptance. Under maximum transmission mode, the electron detection efficiency is more than an order of magnitude better than the previous endstation at beamline 9.3.2. Herein we describe the design and performance of the system, which has been utilized to record spectra above 2 mbar.

Fast vacancy-mediated oxygen ion incorporation across the ceria–gas electrochemical interface

“…The beamline is equipped with a differentially pumped Scienta R4000 HiPP electron analyser, which allowed the sample to be exposed to a gas atmosphere up to 1 Torr (ref. 28). Our homebuilt sample holder provides both heating and electrical contacts 57 .…”

“…For example, density functional calculations predicted reduced defect formation energy on the low-index surfaces of ceria from that of the bulk [20][21][22][23] , which has been validated experimentally 24 . In operando techniques such as in-situ X-ray photoelectron spectroscopy (XPS) [25][26][27][28][29] have also been applied to ceria 16,[30][31][32] . However, many of these experiments adopted electrochemical cell geometries that are bulk-diffusion-limited, rather than surface-reaction-limited.…”

Ambient pressure XPS and IRRAS investigation of ethanol steam reforming on Ni–CeO2(111) catalysts: an in situ study of C–C and O–H bond scission

“…A VG Scienta R4000 HiPP analyzer was used for XPS analysis. 24 The O 1s region was probed with photon energy of 650 eV, and the C 1s, Ni 3p, and Ce 4d 6 regions with photon energy of 490 eV and a resolution of ~0.2 eV. The Ce 4d photoemission lines were used for binding energy calibration based on the 122.8 eV satellite features.…”

Insights into Electrochemical Reactions from Ambient Pressure Photoelectron Spectroscopy

“…[18][19] A typical instrument (Figure 1) consists of a highpressure cell/chamber, separated from the electron analyzer-which remains in high vacuum-by a differentially pumped electrostatic lens system and series of apertures. [20][21] Such instruments are found at synchrotrons around the world [22][23][24][25][26][27] and are being increasingly used with lab X-ray sources as well, which will further empower the field in the years to come. AP-XPS probes the surface chemistry of catalysts at elevated pressures, 29 identifying and quantifying adsorbates in equilibrium with the gas.…”