Trailing 1-0 from the first leg at Stamford Bridge, Chelsea came away from Catalonia with a creditable 1-1 draw as Guro Reiten's effort cancelled out Caroline Graham Hansen's opener.
However, Emma Hayes's side could not breach the Barcelona backline a second time, as the 70,000-strong crowd at Camp Nou witnessed the Catalonian giants set up a showpiece finale with Arsenal or Wolfsburg Women.
The hosts absorbed copious amounts of Chelsea pressure and waited for the right time to launch a sweeping counter-attack, which ended with Graham Hansen breaking the deadlock with 63 minutes gone.
Aitana Bonmati charged through the centre of the field before laying off Graham Hansen on the right, and despite the best efforts of Jess Carter, the Chelsea defender could only deflect the Norwegian's strike into the back of the net.
Hayes's side were not giving up the ghost, though, and they drew themselves level just four minutes later, as Barca goalkeeper Sandra Panos produced a strong close-range stop from Samantha Kerr, but Reiten was on hand to fire home.
Barcelona remained on top heading into the final exchanges, though, as another shot at European glory went begging for Chelsea, who return to Women's Super League action at home to Liverpool on Wednesday.