The second generation of Proterra's battery-electric buses, it succeeded the earlier EcoRide as the company's flagship product.

Catalyst is a modular system, offered with two different lengths, two different drivetrains, and seven different batteries, depending on the required passenger capacity, speed (hill performance),[6] and range, respectively.

[7] At introduction, the Catalyst was equipped with a single electric traction motor, the UQM Technologies HD220.

[10] As ProDrive, the Catalyst was equipped with an upgraded UQM HD250 motor,[2] which offered increased ratings of 250 kW (340 hp) peak power (150 kW (200 hp) continuous) and 900 N⋅m (660 ft⋅lb) peak torque (360 N⋅m (270 ft⋅lb) continuous).

[13] The buses were initially offered with lithium-titanate battery chemistry, which Proterra redesignated the TerraVolt FC.

Two examples of this are the Washington Plaza Bus Terminal in New York and the Mill Woods Transit Center in Edmonton.