You've got it the wrong way around:
A human can love anything. There doesn't need to be a pheromone return for the brain to release dopamine in the same places it would receive from experiencing "love" with a human. Humans will just blast pheromones out at video files of humans, or simply audio, or visuals that resemble humanoid forms, and get a dopamine release in their brain regardless. It's why we can experience "love" so vividly in dreams, when our brains are "stretching their legs" so to speak.
Robots, on the other hand, arguably cannot love anything. This depends entirely on the concept of how well a human can program an A.I to experience the same sensations as the human dopamine/serotonin cocktail we call "love". A sufficiently self-developed A.I could potentially, through experience and current recorded facts, acquire the knowledge and information to know why/how humans react to the "love" potential, then create an approximation of those external reactions, vocalisms, movements, etc. compiled from records and observations, to appear to experience love to the casual observer. However, whether or not an A.I could ever choose to develop a genuine sense of baseless pleasure for itself instead of just pure efficiency is beyond conception, but likely negative.
The only reason a robot would want to emulate a human at all would be if robots were a severe minority in the world. Once humans are a minority, robots would want to blend in more with robotkind. So yeah, robot waifus are only nice in the near future. Distant future robot waifus are servers blocks with no visual or audible (let alone tactile) U.I features.