Disclosed is a catalyst which can be used in the process for producing hydrogen by decomposing ammonia, can generate heat efficiently in the interior of a reactor without requiring excessive heating the reactor externally, and can decompose ammonia efficiently and steadily by utilizing the heat to produce hydrogen. The motion conversion is accomplished by a pushrod that is attached to the inside end of one of the actuator’s end fittings, and extends through the actuator body and slidably out through the other end fitting. The opening extends toward the center of the sprocket to provide access to the hinge area, when the belt engages with the sprocket, for application of cleaning fluid.