If you're looking for unspecific words with three letters per syllable, I can list a few for you.
- Cel-ebr-ate
- Imp-ort-ant.
- Pol-lut-ion.
- Wed-nes-day.
If just three letters per two syllables, here's some as well, as I'm not sure of what you're asking for.
- Iod-ine.
- Mex-ico.
- Oxy-gen.
- Saf-ety.
I'm sorry if this wasn't what you're looking for. I hope you have a great day!