TY - JOUR
T1 - Infiltration and immobilization of catalyst particles into the confined space of microstructured reactors via layer-by-layer self-assembly
AU - Qiu, H.
AU - Bednarova, L.
AU - Lee, W. Y.
PY - 2006/11/9
Y1 - 2006/11/9
N2 - Layer-by-layer (LbL) self-assembly was explored as a new coating method for assembling, infiltrating, and immobilizing catalyst particles in the confined space of microstructured reactors. One layer of negatively charged ∼3 μm Pd/Na-Al(Si)O catalyst particles was electrostatically deposited on Si, SiC, and stainless steel substrates. The substrates were made to be positively charged by applying a ∼20 nm-thick polyelectrolyte multilayer (PEM). The PEM and particle deposition steps were repeated to build a four-layer catalyst particle assembly. Surface coverage, microstructural morphology, and uniformity of the four-layer catalyst particle assembly prepared on the flat Si surface and on the skeleton surface inside the cellular SiC structure with ∼400 μm interconnected cells were similar, demonstrating the non-line-of-sight infiltration attribute of the LbL self-assembly technique. The four-layer assembly deposited on the inner wall of the stainless capillary tube with a 780 μm inner diameter was mechanically stable under a water flow rate up to 10 ml/min over a pH range of 3-11. Scotch tape peeling evaluation suggested that failure locations during peeling were mostly within the catalyst particle assembly, but near the assembly-PEM interface region. The study of catalyst performance in the hydrogenation of acetylene showed that activity and selectivity of the catalyst particles were not affected by the LbL self-assembly procedures.
AB - Layer-by-layer (LbL) self-assembly was explored as a new coating method for assembling, infiltrating, and immobilizing catalyst particles in the confined space of microstructured reactors. One layer of negatively charged ∼3 μm Pd/Na-Al(Si)O catalyst particles was electrostatically deposited on Si, SiC, and stainless steel substrates. The substrates were made to be positively charged by applying a ∼20 nm-thick polyelectrolyte multilayer (PEM). The PEM and particle deposition steps were repeated to build a four-layer catalyst particle assembly. Surface coverage, microstructural morphology, and uniformity of the four-layer catalyst particle assembly prepared on the flat Si surface and on the skeleton surface inside the cellular SiC structure with ∼400 μm interconnected cells were similar, demonstrating the non-line-of-sight infiltration attribute of the LbL self-assembly technique. The four-layer assembly deposited on the inner wall of the stainless capillary tube with a 780 μm inner diameter was mechanically stable under a water flow rate up to 10 ml/min over a pH range of 3-11. Scotch tape peeling evaluation suggested that failure locations during peeling were mostly within the catalyst particle assembly, but near the assembly-PEM interface region. The study of catalyst performance in the hydrogenation of acetylene showed that activity and selectivity of the catalyst particles were not affected by the LbL self-assembly procedures.
KW - Catalyst coating
KW - Hydrogenation of acetylene
KW - Infiltration and immobilization
KW - Layer-by-layer self-assembly
KW - Microstructured reactors or microreactors
KW - Multilayer particle assembly
UR - http://www.scopus.com/inward/record.url?scp=33750077304&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33750077304&partnerID=8YFLogxK
U2 - 10.1016/j.apcata.2006.08.021
DO - 10.1016/j.apcata.2006.08.021
M3 - Article
AN - SCOPUS:33750077304
SN - 0926-860X
VL - 314
SP - 200
EP - 207
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
IS - 2
ER -