A facile strategy is reported for engineering layered double hydroxides (LDHs)-derived nanocomposite catalysts from nano-to macro-scales in one step, via the Al2O3/water interface-assisted method to embed LDHs onto monolithic substrates (such as thin-felt microfibrous structure using 22 mu m FeCrAl fibers or 20 mu m stainless steel fibers and SiC foam) followed by calcination to transform LDHs to nanocomposites. Such approach achieves unique integration of tunability and homogeneous distribution of catalytic components, enhanced heat/mass-transfer, self-supported feature, and high permeability, thus exhibiting tremendous potential for application in harsh reactions. For example, the thin-felt NiO-MgO-Al2O3/FeCrAl-fiber catalyst derived from NiMgAl-LDHs/Al2O3/FeCrAl-fiber offers high activity and stability for the high throughput and exothermic catalytic oxy-methane reforming: 87-90% methane conversion and 91-93/90-92% H-2/CO selectivities at 700 degrees C within 300 h testing, using a high gas hourly space velocity of 72 L g(-1) h(-1). (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.