Answer
$3.21\text{ grams Al}$
Work Step by Step
$2.00 \text{ text L $O_2$}*\frac{1\text{ mol}}{22.42\text{ L}}=0.0892\text{ mol $O_2$}$
$0.0892\text{ mol $O_2$}*\frac{4\text{ mol Al}}{3\text{ mol $O_2$}}*\frac{26.981538\text{ grams Al}}{1\text{ mol Al}}=3.21\text{ grams Al}$