Oligomerization of 1-hexene over designed SBA-15 acid catalysts

•Siliceous SBA-15 materials were synthesized and characterized while controlling their crystallite and pore sizes.•H-Al/SBA-15 and H-SP/SBA-15 acid catalysts were prepared from two different post-synthesis methods.•The 1-hexene oligomerization was investigated under 35bar, 2.0h−1 WHSV, and 200, 100°C, and/or below over the catalysts.•H-SP/SBA-15 optimized with the proper pore size and acid site density exhibited the best catalytic activity.•Controlling the acid sites of H-SBA-15 was a much more critical factor than modifying textural properties.