Is it feasible to recuperate energy from landing aircraft by using a runway sled with regenerative braking?
What you propose might be technically possible, but that doesn't make it a good idea.

However, any benefits would by tiny compared to the immense cost, the extraordinary engineering efforts required, and the horrendous risk of something going wrong.

Airports have long, wide runways for good reasons. Airliners don't touch down on a single spot. Your "sled" would need to be a very wide and extremely long platform.

The sled would need to be able to bear the weight of a large airliner as it touches down. A large plane can damage a concrete runway. The sled is going to need to be extraordinarily strong.

Your platform will need to accelerate from zero to the speed of a landing airliner in very short order; if it causes the plane to decelerate too rapidly instead, it will tear bits off the plane, or limbs and heads off the passengers. 

Good luck designing and manufacturing this huge, strong and and extremely lightweight sled.

(Maybe you can design the sled to match the speed of the incoming plane. That would solve some problems, but only at the expense of introducing some even more exciting new ones, like having just constructed the world's largest and most lethal railgun.)

What's going to happen when something goes wrong? You now have a wheel-less airliner, in difficulties, at landing speed, plus a huge sled also possibly travelling at 300+ km/h. I don't even want to be in the same town as that, never mind at the same airport.

What will you gain? Not much in the way of saved energy from regenerative braking; the energy cost of maintaining the machinery that can cope with such savage braking effects will greatly outweigh it anyway.

And actually, taxiing is good for aircraft engines, because it allows them to warm up before being used at full power (it may even be good for them after landing, to allow them to cool down more slowly).

So, nice idea, but in this case, the wheel, all of 5000+ years old, is an invention better-suited to airliner landings.