2 research outputs found
Vanadium As a Potential Membrane Material for Carbon Capture: Effects of Minor Flue Gas Species
Vanadium
and its surface oxides were studied as a potential nitrogen-selective
membrane material for indirect carbon capture from coal or natural
gas power plants. The effects of minor flue gas components (SO<sub>2</sub>, NO, NO<sub>2</sub>, H<sub>2</sub>O, and O<sub>2</sub>) on
vanadium at 500–600 °C were investigated by thermochemical
exposure in combination with X-ray photoelectron spectroscopy (XPS),
scanning electron microscopy (SEM), and in situ X-ray diffraction
(XRD). The results showed that SO<sub>2</sub>, NO, and NO<sub>2</sub> are unlikely to have adsorbed on the surface vanadium oxides at
600 °C after exposure for up to 10 h, although NO and NO<sub>2</sub> may have exhibited oxidizing effects (e.g., exposure to 250
ppmv NO/N<sub>2</sub> resulted in an 2.4 times increase in surface
V<sub>2</sub>O<sub>5</sub> compared to exposure to just N<sub>2</sub>). We hypothesize that decomposition of surface vanadium oxides and
diffusion of surface oxygen into the metal bulk are both important
mechanisms affecting the composition and morphology of the vanadium
membrane. The results and hypothesis suggest that the carbon capture
performance of the vanadium membrane can potentially be strengthened
by material and process improvements such as alloying, operating temperature
reduction, and flue gas treatment
High Throughput Light Absorber Discovery, Part 2: Establishing Structure–Band Gap Energy Relationships
Combinatorial
materials science strategies have accelerated materials
development in a variety of fields, and we extend these strategies
to enable structure–property mapping for light absorber materials,
particularly in high order composition spaces. High throughput optical
spectroscopy and synchrotron X-ray diffraction are combined to identify
the optical properties of Bi–V–Fe oxides, leading to
the identification of Bi<sub>4</sub>V<sub>1.5</sub>Fe<sub>0.5</sub>O<sub>10.5</sub> as a light absorber with direct band gap near 2.7
eV. The strategic combination of experimental and data analysis techniques
includes automated Tauc analysis to estimate band gap energies from
the high throughput spectroscopy data, providing an automated platform
for identifying new optical materials