Characterization of K-Promoted Ru Catalysts for Ammonia Decomposition Discovered Using High-Throughput Experimentation

Abstract

We obtain H 2 from low temperature NH 3 decomposition using a new hollandite (KRu 4 O 8 ) catalyst supported on c-Al 2 O 3 discovered using high-throughput experimentation and advanced TEM/SEM characterization. Relative to the base Ru°catalyst, this new catalyst shows NH 3 conversion enhancements of 30-50% at T = 350°C and decomposition activity at temperatures decreased by 50-100°C. TEM analysis over the lifetime of the catalyst shows multiple phases and morphologies suggesting that the KRu 4 O 8 behaves either as a new low-temperature decomposition catalyst or as a precursor to the active catalyst.

Material Discovery and High Throughput Exploration of Ru Based Catalysts for Low Temperature Ammonia Decomposition

“…Previous work from our group utilized a response surface methodology to optimize the promoter elements and weight loading for a Ru based catalyst for ammonia decomposition, where the optimal promoter element and loading for 4 wt% Ru/γ-Al 2 O 3 was found to be 12 wt% K [45]. The resultant 4%Ru-12%K/γ-Al 2 O 3 catalyst was chosen as the starting point for our initial high throughput study.…”

Experimental Design for Combinatorial Experiments

“…The most powerful of these methods continues to be Lauterbach's multispectral data cube (Cawse, 2007), which gathers Fourier transform infrared (FTIR) spectral data in parallel from gas streams of multiple catalysts in a "hyperspectral data cube" of gigabyte size. Lauterbach and colleagues have continued to use this methodology to study the mechanism of ammonia decomposition (Pyrz et al, 2008).…”

Ammonia as a Hydrogen Source for Fuel Cells: A Review

“…The support should be stable under reaction conditions and have a high specific surface area. For Ru catalyst, the various supports include silica, alumina, graphitized carbon, carbon nanotubes, and nitrogen doped carbon nanotubes [10,[19][20][21][22][23][24][25]. Yin et al [16] ranked the supports for Ru in order of decreasing activity measured by ammonia conversion rate: Carbon nanotube (CNT) > MgO > TiO2 > Al2O3 > ZrO2 > AC > ZrO2/BD.…”