TPS55340: TPS55340 Reduction Issues

Part Number:TPS55340

Dear E2E :

I use tps55340 for boost  Circuit.  
Input voltage: 12V  ; Output voltage: 24v  Iout=1.5A(max) 
I do test about the basic function, it,s OK. But the reduction Beyond the limit.
so i reduce the switch frequency, But it seems not work.
thanks very much.

Schematic  for Webench,  Something need to be improved or not?

BOT: INPUT Cap not close to the IC.