Exothermic Metal Oxide Metathesis Reactions

Solid-state syntheses of metal oxides frequently involves either high-temperature reactions or precipitation of metal hydroxides that require high-temperature post reaction processing.

 

Carefully designed thermodynamic solid-state metathesis reactions have become an attractive alternative to conventional materials syntheses.  They involve rapid and exothermic exchange reactions that produce nano- or micro-crystalline solids along with a stable byproduct ionic salt such as NaCl.  After washing away the byproduct, the resulting solid sometimes contains a microstructure reminiscent of a composite structure after removal of one component. 

 

                 MX_m + m/n AY_n → MY_z + m AX + (m-z) Y

where M = metal, X = halide, A = alkali metal, Y = non-metal such as N, O, P, As, Se

 

We have been successful in using this method (metal halides reacted with alkali oxides and peroxides) to synthesize nanocrystalline cubic stabilized zirconias and are adapting this methodology to other technologically useful metal oxide structures.

 

Several links to one-page “executive” summaries of recent papers are listed below.  Links to the complete papers are available on the full publications page (see left side bar).

 

Anatase TiO₂ via thermal management of rapid metathesis reactions (submitted)

 

 

Rapid solid-state synthesis of TiO₂ (rutile and anatase) and reduced Ti₂O₃

 

High-temperature stabilized Al-doped TiO₂

 

Stabilized cubic zirconia via rapid metathesis reactions