Synthesis of silver nano catalyst by gel-casting using response surface methodology

Abstract

Ceria supported silver nano catalyst was synthesized using a simple, fast and cost-effective gel‐casting technique. The gel was made of acryl amide monomer (AM) to disperse, stabilize and control the size of metal nanoparticles. The obtained results revealed that nano particles can easily be confined into the three dimensional network of the polymeric gel. The polymer matrix was then removed by calcination under a controlled atmosphere and temperature. A central composite experimental design, which is one of the most popular designs of response surface methodology, was used to optimize the production parameters influencing the surface area and particle size. The studied parameters were the amount of cross-linker (N,N′-methylenebisacrylamide (MBAM)), the monomer (AM) to cross linker ratio and the monomer to salt (silver nitrate) ratio. Two quadratic mathematical model equations were derived for predicting the surface area and particle size. Analysis of the variance showed that the AM/salt ratio was the most significant factor affecting the surface area of nanoparticles. In the process optimization, the maximum amount of surface area was achieved concurrently with the minimum values for particle size at 5.38m2/g and 190nm, respectively. The optimal ranges of the AM/salt ratio and the amount of MBAM to achieve the minimum particle size were 46.97–49.43 and 0.38–0.51, respectively. The optimal values of the MBAM, AM/MBAM and AM/salt ratio for the maximum surface area of 6.09m2/g were found to be 0.54g, 33.92 and 51.89, respectively.