Any computer (with enough resources) can simulate any other computer. So if you have Lisp by running such a simulation (interpreter) on your PC it is not the same thing as a direct implementation of lambda calculus.
The famous Lisp Machines of the 1980s were reasonably traditional Von Neumann computers with nice features like tagged memory and optimized stacks.
Much closer to mechanizing lambda calculus, but still a bit Von Neumannish, is the SECD virtual machine for Lisp and friends:
I'd say no, not on its own. It's not clear how to implement a Lisp program in hardware. You need some steps which today involve a von Neumann architecture and an imperative assembly language that implement Lisp constructs...
The famous Lisp Machines of the 1980s were reasonably traditional Von Neumann computers with nice features like tagged memory and optimized stacks.
Much closer to mechanizing lambda calculus, but still a bit Von Neumannish, is the SECD virtual machine for Lisp and friends:
https://en.wikipedia.org/wiki/SECD_machine