Are there any Catalan speakers who don't speak Spanish?
Yes, mostly in the parts of the Catalan Countries that are not under Spanish occupation. Those are: Northern Catalonia (under French rule, so they speak French), l'Alguer (they speak Italian) and Andorra (an independent country where most people learn both French and Spanish but not everyone will speak both equally well).
That's a map of the Catalan Countries. The parts I've highlighted in red are controlled by the state of Spain: Catalonia, la Franja de Ponent, the Valencian Country and the Balearic Islands. Here, everyone speaks Spanish, it's mandatory by law that we must speak Spanish. Nowadays, it's recognised we also have the right to speak Catalan, but nobody has the obligation to know it. A shitty imperialist law that puts Spanish above the language of the land, but it gives you an idea.
The smaller area I've highlighted in blue is Northern Catalonia, which was annexed by France in 1659. That's before Spanish was imposed in Catalonia, so Northern Catalonia has never spoken Spanish (except like, if someone learned it on their own in the same way you'd learn any other foreign language, but there has not been a state-led programme of Spanish imposition like in the south). Instead of having Spanish imposed on them, they had French.
And the purple part is l'Alguer, in the island of Sardinia (Italy). It's only one city.
In the areas under Spanish rule, there are some people with disabilities who only speak Catalan, and you could also still find a few (but very few) elderly people in rural areas who also only speak Catalan.
There's also foreign people who aren't from the Catalan Countries but who have chosen to learn Catalan. They have to be careful because they are often mistreated by the Spanish police. They have repeatedly reported being harassed by the Spanish police in airports when landing in Catalonia because the Spanish police doesn't believe someone would learn Catalan and not Spanish, so when they can't answer in Spanish they get angry and sometimes arrest them. Catalan people have been sentenced to pay a fine for speaking in Catalan to a Spanish policeman in the airport too (it's considered disrespect of authority to speak to them in Catalan, plus they'll add a bunch of made-up crimes to make you pay a fine for it, even a fine of 200,000€, or they take your passport to make you miss your flight, threaten you, or hit you while shouting anti-catalan slurs against you while waiting at the airport security), but with foreign-born people who don't speak Spanish they literally don't have a choice, they can't do that.
I remember a case from two years ago, there was a Flemish man who lived in a town in Catalonia, he spoke Catalan but not Spanish because everyone in the town spoke Catalan. The cops harassed him, humiliated him in front of everyone, made fun of the fact that he had to wear an ostomy pouching system as a result of a medical operation (basically it's when your digestive and excremental systems don't work correctly so you have a bag connected to your belly that collects the excrements) and the cops forced him to take off his trousers right there in the line to show the excrement bag. Then the cops arrested him and took him to a small room where they reported him for the crimes of perturbing public order. Then they made him get naked, supposedly to show the excrement bag, but then the cops decided they didn't want him to remove his trousers even though it's the only possible way to show it, so they made him take off his shirt for absolutely no reason. They kept him there shirtless and registered his suitcases and interrogated him (all of this, in Spanish which he had said he has a hard time understanding). At one point, the cops asked him the name of the town and wrote it down wrong, then he told them they had clicked the wrong one and repeated the correct one, but the cops got angry for being corrected and reported him for the crime of refusing to cooperate with the police. He was banned from flying and could not go back home. (x)
So yes, there are Catalan speakers who don't speak Spanish, but if you live in the Spanish-occupied part of the Catalan Countries (which is most of it) you have to learn it. If you're born and raised here, there's no way you'll grow up without knowing Spanish even if you don't speak it at home because it's everywhere: on the TV, cinemas, schools, etc.
