The agglomeration and sintering of precious metals such as platinum is a costly problem across a spectrum of catalytic technologies, from those applied in the chemical and petroleum industries to that in pharmaceutical synthesis and auto exhaust catalysis. A new approach to the problem of nanoparticle stabilization, matrix entrapment, was presented. Nano particles were synthesized and incorporated into a matrix of nanoporous carbon (NPC). Reduction at 800°C in flowing hydrogen did not lead to sintering of the particles. The catalysts were quite active even at 400°C for simple reactions, e.g., olefin hydrogenations. HRTEM imaging and XRD revealed that the NPC matrix stabilizes the particles by entrapment. This led to a state that was thermodynamically unstable but for all intent and purposes persistent even under forcing conditions, hence the particles behaved as if they were "frozen" in place because the were unable to locate pathways for transport and sintering since they were too large to move through the nanopores. Hence, the system was "frustrated" kinetically from attaining lower state of chemical potential. This is an abstract of a paper presented at the 227th ACS National Meeting (Anaheim, CA 3/28/2004-4/1/2004).
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)