The alkaline oxygen evolution reaction is a key step in producing green hydrogen through water electrolysis, but its large-scale industrial application remains limited due to challenges with current electrocatalysts—particularly in terms of scalability, efficiency, and long-term stability. Here we show an industrially scalable synthesis of an active NiFe layered double hydroxide (NiFe-LDH) catalyst using a room-temperature, atmospheric-pressure route. The process involves homogeneous alkalinization, where chloride ions nucleophilically attack an epoxide ring, producing a low-dimensional, defect-rich NiFe-LDH with pronounced iron clustering. In-situ spectroscopy and ab-initio calculations reveal that these structural features maximize the conversion of the NiFe-LDH to the catalytic active phase and minimize the energy barrier, improving catalytic efficiency. When used as the anode in an anion exchange membrane water electrolyzer operating at 70 °C, our material delivers 1 A cm⁻² at 1.69 V in a 5 cm2 full-cell setup, with notable durability compared to conventional NiFe-LDHs. This scalable approach could considerably lower the cost of green hydrogen production by enabling more efficient alkaline electrolyzers.
1 September 2012 in Review of Scientific Instruments
A new beam line for medium energy ion mass scattering (MEIS) has been designed and set up at the Ångström laboratory, Uppsala University, Sweden. This MEIS system is based on a time-of-flight (ToF) concept and the electronics for beam chopping relies on a 4 MHz function generator. Repetition rates can be varied between 1 MHz and 63 kHz and pulse widths below 1 ns are typically obtained by including beam bunching. A 6-axis goniometer is used at the target station. Scattering angle and energy of backscattered ions are extracted from a time-resolved and position-sensitive detector. Examples of the performance are given for three kinds of probing ions, 1H+, 4He+, and 11B+. Depth resolution is in the nanometer range and 1 and 2 nm thick Pt layers can easily be resolved. Mass resolution between nearby isotopes can be obtained as illustrated by Ga isotopes in GaAs. Taking advantage of the large size detector, a direct imaging (blocking pattern) of crystal channels are shown for hexagonal, 4H-SiC. The ToF-MEIS system described in this paper is intended for use in semiconductor and thin film areas. For example, depth profiling in the sub nanometer range for device development of contacts and dielectric interfaces. In addition to applied projects, fundamental studies of stopping cross sections in this medium energy range will also be conducted.
3 December 2010 in The Journal of Physical Chemistry B