This research studied a new route for the direct synthesis of benzaldehyde from toluene and hydrogen peroxide in a bubble reactor using titanium silicalite-1 catalysts modified with different amount of Al. The reaction is carried out at atmospheric pressure. Parameters investigated are amount of aluminium, crystallization time, and hydrogen peroxide concentration. The study found that all modified catalysts yield benzaldehyde as the major product with a small amount of o-cresol and p-cresol as by products. The experimental results also show that Al added into TS-1 promotes the formation of benzaldehyde and suppresses the formation of cresols. Too much Al added, however, will increase the decomposition of hydrogen peroxide which results in lower reaction products formed.